Not Shaken, Not Stirred: The Mixed Question of Law and Fact

Mixed Questions of Law and Fact Have Long Eluded Clear Judicial Consensus.

One of law’s perplexing phrases is “the mixed question of law and fact.” The noted torts professor Francis H. Bohlen called the phrase “unfortunate.”⁷⁵ An opinion of the Court of Claims called the plural of the phrase “elusive abominations.”⁷⁶

Federal courts differ as to the meaning of this frequently used phrase, how a district court should decide a mixed question, and the standard of review an appellate court should use when a trial court has decided a mixed question.

Meaning of the Phrase “Mixed Question of Law and Fact”

An initial uncertainty about the meaning of the phrase arises from the word “mixed.” The word does not mean that a question of law and a question of fact have been mixed together in the way that gin and vermouth are mixed together to make a martini.⁷⁷ Instead, the question of law and the question or questions of fact remain distinct; they have simply been combined into what is called a mixed question of law and fact. The phrase might be better rendered as “a combined question of law and fact,” but it is too late in the day to change the wording of a phrase that has been used in more than 10,000 court opinions.⁷⁸

The phrase could mean (1) the two components of the phrase — that is, a question of law and a question of fact; (2) a combination of these two components plus a third component, the application of law to the facts; or (3) just that third component, application, alone. Federal courts have usually used that third meaning.⁷⁹ In 1982, the U.S. Supreme Court characterized a mixed question of law and fact as requiring a determination of “whether the rule of law as applied to the established facts is or is not violated.”⁸⁰ In 2018, the Court articulated the concept of a mixed question reciprocally, explaining that when historical facts are either admitted or established and the rule of law is undisputed, the remaining issue is whether those facts meet the statutory standard.⁸¹

Should a Judge or Jury Decide a Mixed Question in a District Court?

In a nonjury case, the district judge decides the entirety of the mixed question of law and fact. The judge finds the facts, determines which law is applicable, and applies that law to the facts found.

In a jury case, the jury finds the facts, and the judge determines which law is applicable. Controversy has arisen over whether the judge or the jury should apply the law, as determined by the judge, to the facts, as determined by the jury, to rule on the mixed question of law and fact.

In a jury case, it might seem that how the relevant law applies to the facts is itself an issue of law, and therefore a district judge should decide how the law applies to the facts that the jury has found. That would be easy to accomplish if a case contained only a few factual disputes. The judge could direct the jury to return “special verdicts,” i.e., inform the judge how the jury decided those few factual disputes. Once the judge had the special verdicts, the judge could then perform the legal task of applying the law to the facts that the jury found. This happens from time to time but relatively rarely.

The question of who applies the law to the facts becomes difficult when, as frequently occurs, many factual disputes are involved. Even if the case appears to present only one factual issue — for example, did the defendant injure the plaintiff? — that ultimate factual issue comprises many subsidiary issues: Did any witnesses see the incident? How far away from the incident were they standing? Did they have a direct line of sight? How much light existed at the place and time of the incident? Could the witnesses recall accurately what they saw? Did any of the witnesses have some reason to shade their testimony in favor of or against either of the parties? Some seemingly simple factual issues comprise many subsidiary issues.

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[“Mixed”] does not mean that a question of law and a question of fact have been mixed together in the way that gin and vermouth are mixed together to make a martini. Instead, the question of law and the question or questions of fact remain distinct; they have simply been combined into what is called a mixed question of law and fact.

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In such cases, there are three possible answers to the question of who applies the law to the facts: (1) the judge, in the jury instructions, could inform the jury how the law would apply to all the possible facts that the jury might find and then the jury would apply the law to all the facts that it found; (2) the judge could ask the jury to answer a large number of factual issues and then the judge could apply the law to all the facts that the jury found; (3) the judge, in the jury instructions, could inform the jury about the relevant law in somewhat general language and instruct the jury that it should apply the law to the facts that it has found.

Before Oliver W. Holmes Jr. became Justice Holmes, he described the first possibility: “If there is such a dispute [as to what happened], it is entirely possible to give a series of hypothetical instructions adapted to every state of facts which it is open to the jury to find.”⁸² However, Bohlen pointed out the obvious difficulty of that approach:

[S]ince it is impossible to anticipate the innumerable combinations of circumstances which may arise, it is impossible for the law to formulate in advance definite standards by which the propriety of conduct under every conceivable set of circumstances may be judged.⁸³

Facing that reality, Bohlen concluded, “[The Court] can at best announce broad general principles, which give [the jury] general directions for the construction of the standard to be applied in each specific case.”⁸⁴ That, in effect, is the third approach.

Standard of Review an Appellate Court Uses for a District Court Ruling on a Mixed Question

Preliminarily, it should be noted that some appellate court opinions, considering the appropriate standard of review in mixed question cases, incorrectly say that the appellate court is reviewing the mixed question of law and fact.⁸⁵ What the appellate court is reviewing is a district court’s ruling on a mixed question of law and fact.

In 1982, the Supreme Court acknowledged in Pullman-Standard v. Swint that its decisions on the standard of review for rulings on mixed questions had not been consistent.⁸⁶ The Court noted that it had sometimes reviewed such rulings independently, i.e., de novo⁸⁷ (treating the question as one of law and giving no deference to the district court’s ruling), and sometimes reviewed them under the clearly erroneous standard⁸⁸ (treating the question as one of fact and permitting rejection of a district court’s finding of fact only if an appellate court “is left with the definite and firm conviction that a mistake has been committed”⁸⁹).

Caselaw reveals four approaches to appellate review of a district court’s ruling on a mixed question of law and fact.⁹⁰ One approach gives de novo review to the ruling.⁹¹ A second approach reviews the ruling for clear error.⁹² A third approach separately considers the fact question(s) and the legal question(s), applying clearly erroneous review to the ruling on the fact question(s) and de novo review to the law question(s).⁹³ A variant of the third approach gives de novo review to the fact question(s) where constitutional considerations are involved.⁹⁴

A fourth approach first determines whether the mixed question predominantly involves a dispute about the facts — in which event the clearly erroneous standard is applied to the ruling — or whether the mixed question predominantly involves a question of law — in which case the de novo standard is applied to the ruling.⁹⁵ The Supreme Court adopted this “predominance approach” in 2018 in U.S. Bank National Ass’n v. Village at Lakeridge, LLC.⁹⁶

Evolution of the Predominance Approach

Although a Fifth Circuit opinion in 1976 mentioned “predominance” of factual questions over legal issues as a reason for using clear error review, it was a 1984 Ninth Circuit opinion written by Judge William Norris called United States v. McConney⁹⁷ that articulated a rationale for the predominance approach. The issue in McConney was whether exigent circumstances existed for a warrantless search. Norris wrote:

[T]he key to the resolution of this question is the nature of the inquiry that is required to decide “whether the rule of law as applied to the established facts is or is not violated.” If application of the rule of law to the facts requires an inquiry that is “essentially factual” — one that is founded “on the application of the fact-finding tribunal’s experience with the mainsprings of human conduct” — the concerns of judicial administration will favor the district court, and the district court’s determination should be classified as one of fact reviewable under the clearly erroneous standard. If, on the other hand, the question requires us to consider legal concepts in the mix of fact and law and to exercise judgment about the values that animate legal principles, then the concerns of judicial administration will favor the appellate court, and the question should be classified as one of law and reviewed de novo.⁹⁸

Norris noted that “[t]he predominance of factors favoring de novo review is even more striking when the mixed question implicates constitutional rights.”⁹⁹

Three years later, a Fifth Circuit opinion written by Judge John Minor Wisdom, considering a ruling on the mixed question of law and fact as to whether agency had been established, concluded, “This predominance of factual issues demands that we apply the ‘clearly erroneous’ standard of review in this case.”¹⁰⁰

Several courts of appeals later adopted the predominance approach.¹⁰¹

The Supreme Court’s path to the predominance approach has not been a straight line. In 1925, the Court wrote, “[W]here a finding determines a mixed question of law and fact, it is conclusive unless the court is able to separate the question to see whether there is a mistake of law.”¹⁰² In 1927, the Court said that in dealing with a mixed question of law and fact, “[W]e may review the facts in order correctly to apply the law.”¹⁰³ In 1937, the Court wrote that upon review of a mixed question of law and fact “the court may substitute its judgment for that of the Board [of Tax Appeals].”¹⁰⁴ In 1943, the Court said, “[i]t is difficult to lay down rules as to what should or should not be reviewed in tax cases except in terms so general that their effectiveness in a particular case will depend largely upon the attitude with which the case is approached.”¹⁰⁵

In 1985, the Court said, “[p]erhaps much of the difficulty in this area stems from the practical truth that the decision to label a ‘question of law,’ a ‘question of fact,’ or a ‘mixed question of law and fact’ is sometimes as much a matter of allocation as it is of analysis.”¹⁰⁶ The Court also noted that the decision as to review “has turned on a determination that, as a matter of the sound administration of justice, one judicial actor is better positioned than another to decide the issue in question.”¹⁰⁷ And the Court again acknowledged that “the Court has not charted an entirely clear course in this area.”¹⁰⁸

In 1991, the Court said, “we have held that deferential review of mixed questions of law and fact is warranted when it appears that the district court is ‘better positioned’ than the appellate court to decide the issue in question or that probing appellate scrutiny will not contribute to the clarity of legal doctrine.”¹⁰⁹ In 1992, Justice Sandra Day O’Connor referred to “the settled principle that mixed questions are subject to plenary review on federal habeas corpus.”¹¹⁰ In 1995, the Court said that “a ‘mixed question of law and fact,’ has typically been resolved by juries.”¹¹¹

Amidst these rulings, in the 1985 case of Wainwright v. Witt, the Supreme Court gave its first hint of a predominance approach to determine the appropriate standard of review of a ruling on a mixed question.¹¹² The case concerned a habeas corpus challenge to a state court conviction brought under 28 U.S.C. § 2254(d). The Court considered the standard of review appropriate for a district court’s determination that a prospective juror was not subject to challenge for cause on the basis of somewhat ambiguous responses to questions about opposition to the death penalty. After noting that “[i]t will not always be easy to separate questions of ‘fact’ from ‘mixed questions of law and fact’ for § 2254(d) purposes,”¹¹³ the Court wrote:

The trial judge is of course applying some kind of legal standard to what he sees and hears, but his predominant function in determining juror bias involves credibility findings whose basis cannot be easily discerned from an appellate record.”¹¹⁴

The Court concluded that “the question of challenge for bias is a ‘factual issue’ covered by [28 U.S.C. § 2254(d)].”¹¹⁵ And the habeas corpus statute provides that in proceedings brought by those in state custody, “a determination of a factual issue made by a State court shall be presumed to be correct.”¹¹⁶

In 1990, the Court considered what standard of review applied to a “district court’s legal conclusions in Rule 11 [of the Federal Rules of Civil Procedure] proceedings.”¹¹⁷ The Court concluded that an “abuse of discretion” standard was applicable,¹¹⁸ a standard the Court said was “indistinguishable” from a clearly erroneous standard.¹¹⁹ The Court explained that “the district court is better situated than the court of appeals to marshal the pertinent facts and apply the fact-dependent legal standard mandated by Rule 11.”¹²⁰

Again, the hint of the predominance approach appeared. To the extent that the district court needed to “marshal the pertinent facts” and resolve any disputes about them, that court of course was better situated than the court of appeals to perform these tasks because that is what a district court does.¹²¹

In 1999, Chief Justice William Rehnquist, referring to a mixed question of law and fact, wrote in a concurring opinion that “the mix weighs heavily on the ‘fact’ side.”¹²²

In 2011, the Court incorporated Rehnquist’s remark into a Court opinion: “The ultimate issue . . . presents a mixed question of law and fact; but there, too, ‘the mix weighs heavily on the ‘fact’ side.'”¹²³

Then, in 2018, in U.S. Bank,¹²⁴ the Court adopted the predominance approach for review of rulings on mixed questions. The issue was whether a creditor of a debtor in bankruptcy was a non-statutory insider, in which event his consent to a “cramdown” reorganization plan would not permit approval of the plan.¹²⁵

The Court asked, “What is the nature of the mixed question here and which kind of court (bankruptcy or appellate) is better suited to resolve it?”¹²⁶ Answering that question, the Court concluded, “[T]he standard of review for a mixed question all depends — on whether answering it entails primarily legal or factual work.”¹²⁷ The adverb “primarily” signaled the Court’s adoption of the predominance approach.¹²⁸

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The Court concluded, “the standard of review for a mixed question all depends — on whether answering it entails primarily legal or factual work.” The adverb “primarily” signaled the Court’s adoption of the predominance approach.

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Implementing the predominance approach, the Court then observed, “[T]he mixed question became: Given all the basic facts found, was Rabkin’s [alleged insider] purchase of MBP’s claim conducted as if the two were strangers to each other? That is about as factual sounding as any mixed question gets.”¹²⁹

In 2020, the Court, considering a district court’s ruling on a child’s “habitual residence” for purposes of the Hague Convention on the Civil Aspects of International Child Abduction, repeated the formula articulated in U.S. Bank: “[T]he appropriate standard of appellate review for a mixed question ‘depends . . . on whether answering it entails primarily legal or factual work.'”¹³⁰ Thus was the predominance approach solidified. And later in 2020, the Court again articulated the predominance approach:

The answer to the “proper standard” question may turn on practical considerations, such as whether the question primarily “requires courts to expound on the law, particularly by amplifying or elaborating on a broad legal standard” (often calling for review de novo), or rather “immerses courts in case-specific factual issues” (often calling for deferential review).¹³¹

In 2021, in Google LLC v. Oracle Am., Inc.,¹³² the Court articulated the third approach (reviewing separately the fact question(s) and the law question(s) under the appropriate standards), but then added this significant sentence: “But when a question can be reduced no further, we have added that ‘the standard of review for a mixed question all depends — on whether answering it entails primarily legal or factual work,'” citing U.S. Bank.¹³³ Although it is not entirely clear what the Court meant by the clause “when a question can be reduced no further,” the Google case indicates that the Court was continuing to apply the predominance approach.¹³⁴

In 2024, however, in Wilkinson v. Garland,¹³⁵ the Court issued an opinion containing language that seemed to depart from the predominance approach. A noncitizen had sought to prevent his removal on the ground that it would cause extreme hardship to his citizen son. An immigration judge (IJ) had ruled that the noncitizen had not met the statutory standard for extreme hardship. On petition for review, the Third Circuit dismissed, ruling that the IJ had made a discretionary decision and that the court of appeals had jurisdiction to review only a ruling on a question of law.¹³⁶ The Supreme Court reversed, holding that the IJ’s application of law to the facts was a ruling on a question of law over which the Court had jurisdiction.¹³⁷

Although the Court’s holding is understandable, the Court’s explanation of the holding casts doubt on the predominance approach. Initially, the Court recognized that the application of the statutory hardship standard to the facts of the case was a mixed question of law and fact.¹³⁸ The Court then questionably stated, “[t]hat a mixed question requires a court to immerse itself in facts does not transform the question into one of fact. It simply suggests a more deferential standard of review.”¹³⁹ Finally, the Court surprisingly noted, “[a] mixed question that requires close engagement with the facts is still a mixed question, and it is therefore a ‘question of law.'”¹⁴⁰

Despite the available inference from this language that the Court was not using the predominance approach, the Court might have thought it was being faithful to that approach — as evidenced by the fact that it not only cited U.S. Bank but also quoted a key passage from that decision: “A mixed question may require ‘primarily legal or factual work.'”¹⁴¹

Any doubt about the Court’s adherence to the predominance approach was allayed by the Court’s 2025 decision in Bufkin v. Collins.¹⁴² Citing U.S. Bank, the Court in Bufkin wrote, “the appropriate standard of review for a mixed question depends ‘on whether answering it entails primarily legal or factual work.'”¹⁴³ And, tellingly, the Court added, “[w]hen the tribunal below is ‘immersed’ in facts and compelled to ‘marshal and weigh evidence’ and ‘make credibility judgments,’ the appellate court ‘should usually review a decision with deference,'”¹⁴⁴ i.e., use the clearly erroneous standard of review. This sentence unequivocally rejected the questionable language in Wilkinson: “A mixed question that requires close engagement with the facts is still a mixed question, and it is therefore a ‘question of law.'”¹⁴⁵

Analysis of the Predominance Approach

It is a fair question whether the applicable standard of review of a ruling on a mixed question of law and fact should depend on whether answering the question entails primarily legal or factual work. No matter how many factual questions a district court (or a jury) resolves, determining how the relevant legal standard applies to the facts is a legal issue.¹⁴⁶ Applying the relevant legal standard to the facts refines what is often a broadly worded standard and gives it particularized meaning. That sounds like a legal task.

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Perhaps what determines whether the standard of review is de novo or clearly erroneous, at least in some cases, is the importance courts attach to producing a fairly clear ruling of law on the issue at hand.

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Perhaps what determines whether the standard of review is de novo or clearly erroneous, at least in some cases, is the importance courts attach to producing a fairly clear ruling of law on the issue at hand. With probable cause, courts might deem it important to have a clear standard to guide future police conduct. Using a de novo standard of review affords courts the opportunity to fashion legal standards that implement the protections of the Fourth Amendment.¹⁴⁷ On the other hand, with issues like negligence, courts might not deem it important (or practical) to fashion a clear standard — one that would be more precise than something like “reasonable care under the circumstances” — to guide the future conduct of all persons who might have inflicted harm. Courts are therefore willing to leave the issue of negligence to the jury, or to the court in a nonjury case, and generally accept its decision, using a very deferential standard of review.¹⁴⁸

Some initial research suggests these two patterns, applicable to probable cause and negligence, might exist, but the question of the extent to which the underlying substantive law might affect the standard of review deserves further study.

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JON O. NEWMAN is a senior judge on the U.S. Court of Appeals for the Second Circuit. He is serving his 54th year as a federal judge.

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1. Francis H. Bohlen, Mixed Questions of Law and Fact, 72 U. Pa. L. Rev. 111, 112 (1924).
2. S & E Contractors. Inc. v. U.S., 433 F.2d 1373, 1378 (Ct. Cl. 1970), rev'd without consideration of this point, 406 U.S. 1 (1972).
3. My thanks to Amelia Thorn for cleverly putting this thought into the title of this article.
4. Westlaw limits to 10,000 cases a search request retrieving more than 10,000 cases containing usages of a word or phrase. A search for the variation "mixed question of fact and law" retrieved 6,207 cases. A search for "mixed question of law and facts" retrieved 59 cases. A search for "mixed question of facts and law" retrieved 19 cases. The phrase "mixed question of law and fact" first appeared in a federal court opinion in 1807, Winthrop v. Union Ins., 30 F. Cas. 376, 382 (C.C.D. Pa. 1807).
5. See, e.g., Guerrero-Lasprilla v. Barr, 589 U.S. 221, 230–31 (2020) ("Congress understood the statutory term 'question of law and fact' to include the application of law to facts."); Gasparyan v. Holder, 707 F.3d 1130, 1134 (9th Cir. 2013) ("Mixed questions of law and fact refer to the application of law to undisputed facts.") (internal quotation marks and citations omitted).
6. Pullman-Standard v. Swint, 456 U.S. 273, 289 n.19 (1982).
7. U.S. Bank Nat. Ass'n v. Vill. at Lakeridge, LLC, 583 U.S. 387, 394 (2018) (citing Pullman-Standard, 456 U.S. at 289 n.19).
8. Oliver W. Holmes Jr., The Common Law 122 (1881).
9. Bohlen, supra note 1, at 113.
10. Id.
11. See Singh v. Rosen, 984 F.3d 1142, 1148 (6th Cir. 2021) ("[R]eview the question . . . ."); United States v. Kinslow, 105 F.3d 555, 557 (10th Cir. 1997) ("[R]eview mixed questions . . .") (quoting Armstrong v. Comm'r, 15 F.3d 970, 973 (10th Cir. 1994)).
12. 456 U.S. at 289 n.19.
13. See id. (citing Bogardus v. Comm'r, 302 U.S. 34, 39 (1937) and Helvering v. Tex-Penn Oil Co., 300 U.S. 481, 491 (1937)).
14. See id. (citing Comm'r v. Duberstein, 363 U.S. 278, 289 (1960), and Comm'r v. Heininger, 320 U.S. 467, 475 (1943)).
15. United States v. U.S. Gypsum Co., 333 U.S. 364, 395 (1948).
16. For consideration of the somewhat related issue of the standard of review for a mixed question of fact and discretion, see Gwendolyn Savitz, Reviewing Mixed Questions of Fact and Law in Administrative Adjudications: Why Courts Should Move to "Substantially Established Facts," 68 Vill. L. Rev. 463, 468–71 (2023); Kevin Casey et al., Standards of Appellate Review in the Federal Circuit: Substance and Semantics, 11 Fed. Cir. B.J. 279, 321 (2002) (referring to the approach of the federal circuit to "mixed questions of fact and discretion").
17. E.g., Ornealas v. United States, 517 U.S. 690, 691 (1996); United States v. Fiseku, 915 F.3d 863, 869 (2d Cir. 2018); Razavi v. Comm'r, 74 F.3d 125, 127 (6th Cir. 1996).
18. E.g., Duberstein, 363 U.S. at 289; Rogers v. Bates, 431 F.2d 16, 18 (8th Cir. 1970); Pennsylvania Cas. Co. v. McCoy, 167 F.2d 132, 133 (5th Cir. 1948).
19. E.g., Google LLC v. Oracle Am., Inc., 593 U.S. 1, 24 (2021) (noting that for mixed questions, "a reviewing court should try to break such a question into its separate factual and legal parts, reviewing each according to the appropriate legal standard"); Alom v. Whitaker, 910 F.3d 708, 713 (2d Cir. 2018) (same); Church of Scientology of California v. Comm'r, 823 F.2d 1310, 1320 (9th Cir. 1987) (same).
20. E.g., Bose Corp. v. Consumers Union of U.S., Inc., 466 U.S. 485, 499 (1984) ("[I]n cases raising First Amendment issues we have repeatedly held that an appellate court has an obligation to 'make an independent examination of the whole record' in order to make sure that 'the judgment does not constitute a forbidden intrusion on the field of free expression.'") (quoting New York Times Co. v. Sullivan, 376 U.S. 254, 285 (1964)); Church of Scientology, 823 F.2d at 1320 (applying de novo review "when questions of motive implicate constitutional rights"); United States v. McConney, 728 F.2d 1195, 1203 (9th Cir. 1984) (en banc) ("The predominance of factors favoring de novo review is even more striking when the mixed question implicates constitutional rights.").
21. See Singh, 984 F.3d at 1148 ("Courts follow a case-by-case approach when choosing a standard of review for mixed questions. If a question is more fact intensive, they typically review the question with deference; if it is more legal, they typically review it de novo."); Kinslow, 105 F.3d at 557 (same).
22. See 583 U.S. at 396.
23. See 728 F.2d at 1202–04 (noting Judge Norris delivered Part II of the court's opinion, joined by Judges Fletcher, Nelson, and Canby, as inferred from the syllabus and their absence as concurring in or writing the opinions of the other members of the en banc court).
24. Id. at 1202 (internal quotation marks and citations omitted).
25. Id. at 1203 (emphasis added).
26. Am. Int'l Trading Corp. v. Petroleos Mexicanos, 835 F.2d 536, 539 (5th Cir. 1987) (emphasis added) (citation omitted).
27. E.g., Uzdavines v. Weeks Marine, Inc., 418 F.3d 138, 143 (2d Cir. 2005) (reviewing "mixed questions of law and fact either de novo or under the clearly erroneous standard depending on whether the question is predominantly legal or factual"); In re Computer Eng'g Assocs., Inc., 337 F.3d 38, 45 (1st Cir. 2003) ("We review . . . mixed questions somewhere on a sliding scale between de novo and clear error review depending on how fact dominated the question."); Charter Communications, Inc. v. County of Santa Clara, 304 F.3d 927, 930 (9th Cir. 2002) ("[T]o the extent that a mixed question presents an 'essentially' factual inquiry, then review is for clear error."); Anderson v. Comm'r, 62 F.3d 1266, 1270 (10th Cir. 1995) ("We review mixed questions of law and fact either under the clearly erroneous standard or de novo, depending on whether the mixed question is primarily factual or legal.").
28. Stilz v. United States, 269 U.S. 144, 147–48 (1925).
29. First Nat. Bank v. City of Hartford, 273 U.S. 548, 552 (1927).
30. Tex-Penn Oil Co., 300 U.S. at 491.
31. Dobson v. Comm'r, 320 U.S. 489, 501 (1943).
32. Miller v. Fenton, 474 U.S. 104, 113–14 (1985) (citation omitted).
33. Id. at 114.
34. Id. at 113.
35. Salve Regina Coll. v. Russell, 499 U.S. 225, 233 (1991) (citation omitted).
36. Wright v. West, 505 U.S. 277, 309 (1992) (O'Connor, J., concurring) (citation omitted).
37. United States v. Gaudin, 515 U.S. 506, 512 (1995).
38. 469 U.S. 412, 428 (1985). Arguably, the Court was moving toward the predominance approach as early as Duberstein in 1960, where it recognized that an issue of intent was "essentially factual, subject to the clearly-erroneous rule." Pullman-Standard, 456 U.S. at 288 (emphasis added) (citing Duberstein, 363 U.S. at 286).
39. Wainwright, 469 U.S. at 429 (citation omitted).
40. Id. (emphasis added).
41. Id. at 430.
42. 28 U.S.C. § 2254(e)(1).
43. Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 401 (1990). Rule 11 of the Federal Rules of Civil Procedure authorizes a district court to impose sanctions on an attorney who fails to abide by requirements intended to prevent frivolous litigation. Fed. R. Civ. P. 11(c).
44. Id. at 409.
45. Id. at 401.
46. Id. at 402.
47. Id.
48. Lilly v. Virginia, 527 U.S. 116, 148 (1999) (Rehnquist, C.J., concurring) (emphasis added).
49. Brown v. Plata, 563 U.S. 493, 517 (2011) (Rehnquist, C.J., concurring) (emphasis added) (quoting Lilly, 527 U.S. at 148).
50. 583 U.S. at 396.
51. Id. at 387.
52. Id. at 395 (citing this language from the 1985 decision in Fenton, 474 U.S. at 114: "When an 'issue falls somewhere between a pristine legal standard and a simple historical fact,' the standard of review often reflects which 'judicial actor is better positioned' to make the decision.").
53. Id. at 396 (emphasis added).
54. Id.
55. Id. at 388.
56. Monasky v. Taglieri, 589 U.S. 68, 83–84 (2020) (emphasis added).
57. Guerrero-Lasprilla, 589 U.S. at 228 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396) (brackets removed).
58. 593 U.S. 1 (2021).
59. 593 U.S. at 24 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
60. See id.
61. 601 U.S. 209 (2024).
62. Wilkinson v. Att'y Gen. United States, No. 21-3166, 2022 WL 4298337, at *2 (3d Cir. Sept. 19, 2022).
63. Wilkinson, 601 U.S. at 217.
64. Id. at 212.
65. Id. at 222.
66. Id. (emphasis added) (brackets removed).
67. Id. at 222 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
68. 145 S. Ct. 728 (2025).
69. Id. at 739 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
70. Id. (quoting U.S. Bank, 583 U.S. at 396) (brackets removed).
71. Wilkinson, 601 U.S. at 222 (citation omitted) (brackets removed).
72. One critic of the predominance approach has written, "It cannot be that deciding whether review is de novo or deferential — the single most important factor in determining whether an appeal will succeed — simply requires adding up the facts in dispute and determining whether legal or factual issues predominate." Randall H. Warner, All Mixed Up About Mixed Questions, 7 J. App. Prac. & Process 101, 109 (2005).
73. See, e.g., Ornealas, 517 U.S. at 698–699 (demonstrating that de novo review of probable cause determinations safeguards the Fourth Amendment by incentivizing police to seek warrants, since a magistrate's probable-cause determination is subject to less stringent scrutiny than warrantless searches); Ker v. California, 374 U.S. 23, 33 (1963) (emphasizing that appellate courts must independently articulate and enforce constitutional standards, particularly those governing probable cause, to safeguard Fourth Amendment protections, rather than deferring entirely to trial court determinations).
74. See, e.g., Elberg v. Mobil Oil Corp., 967 F.2d 1146, 1149 (7th Cir. 1992) (stating that "[a] determination that particular facts constitute negligence involves a mixed question of law and fact that is reviewed under the clearly erroneous standard" and affirming the jury's verdict); Miller v. United States, 587 F.2d 991, 994 (9th Cir. 1978) (emphasizing that negligence determinations are mixed questions of law and fact whose ultimate application is reviewed only for clear error and demonstrating how appellate courts accord substantial deference to trial-level negligence findings); see generally Wright & Miller's Federal Practice & Procedure § 2590 Mixed Questions of Fact and Law–Negligence Cases (3d ed. 2024).
75. Francis H. Bohlen, Mixed Questions of Law and Fact, 72 U. Pa. L. Rev. 111, 112 (1924).
76. S & E Contractors. Inc. v. U.S., 433 F.2d 1373, 1378 (Ct. Cl. 1970), rev’d without consideration of this point, 406 U.S. 1 (1972).
77. My thanks to Amelia Thorn for cleverly putting this thought into the title of this article.
78. Westlaw limits to 10,000 cases a search request retrieving more than 10,000 cases containing usages of a word or phrase. A search for the variation “mixed question of fact and law” retrieved 6,207 cases. A search for “mixed question of law and facts” retrieved 59 cases. A search for “mixed question of facts and law” retrieved 19 cases. The phrase “mixed question of law and fact” first appeared in a federal court opinion in 1807, Winthrop v. Union Ins., 30 F. Cas. 376, 382 (C.C.D. Pa. 1807).
79. See, e.g., Guerrero-Lasprilla v. Barr, 589 U.S. 221, 230–31 (2020) (“Congress understood the statutory term ‘question of law and fact’ to include the application of law to facts.”); Gasparyan v. Holder, 707 F.3d 1130, 1134 (9th Cir. 2013) (“Mixed questions of law and fact refer to the application of law to undisputed facts.”) (internal quotation marks and citations omitted).
80. Pullman-Standard v. Swint, 456 U.S. 273, 289 n.19 (1982).
81. U.S. Bank Nat. Ass’n v. Vill. at Lakeridge, LLC, 583 U.S. 387, 394 (2018) (citing Pullman-Standard, 456 U.S. at 289 n.19).
82. Oliver W. Holmes Jr., The Common Law 122 (1881).
83. Bohlen, supra note 1, at 113.
84. Id.
85. See Singh v. Rosen, 984 F.3d 1142, 1148 (6th Cir. 2021) (“[R]eview the question . . . .”); United States v. Kinslow, 105 F.3d 555, 557 (10th Cir. 1997) (“[R]eview mixed questions . . .”) (quoting Armstrong v. Comm’r, 15 F.3d 970, 973 (10th Cir. 1994)).
86. 456 U.S. at 289 n.19.
87. See id. (citing Bogardus v. Comm’r, 302 U.S. 34, 39 (1937) and Helvering v. Tex-Penn Oil Co., 300 U.S. 481, 491 (1937)).
88. See id. (citing Comm’r v. Duberstein, 363 U.S. 278, 289 (1960), and Comm’r v. Heininger, 320 U.S. 467, 475 (1943)).
89. United States v. U.S. Gypsum Co., 333 U.S. 364, 395 (1948).
90. For consideration of the somewhat related issue of the standard of review for a mixed question of fact and discretion, see Gwendolyn Savitz, Reviewing Mixed Questions of Fact and Law in Administrative Adjudications: Why Courts Should Move to “Substantially Established Facts,” 68 Vill. L. Rev. 463, 468–71 (2023); Kevin Casey et al., Standards of Appellate Review in the Federal Circuit: Substance and Semantics, 11 Fed. Cir. B.J. 279, 321 (2002) (referring to the approach of the federal circuit to “mixed questions of fact and discretion”).
91. E.g., Ornealas v. United States, 517 U.S. 690, 691 (1996); United States v. Fiseku, 915 F.3d 863, 869 (2d Cir. 2018); Razavi v. Comm’r, 74 F.3d 125, 127 (6th Cir. 1996).
92. E.g., Duberstein, 363 U.S. at 289; Rogers v. Bates, 431 F.2d 16, 18 (8th Cir. 1970); Pennsylvania Cas. Co. v. McCoy, 167 F.2d 132, 133 (5th Cir. 1948).
93. E.g., Google LLC v. Oracle Am., Inc., 593 U.S. 1, 24 (2021) (noting that for mixed questions, “a reviewing court should try to break such a question into its separate factual and legal parts, reviewing each according to the appropriate legal standard”); Alom v. Whitaker, 910 F.3d 708, 713 (2d Cir. 2018) (same); Church of Scientology of California v. Comm’r, 823 F.2d 1310, 1320 (9th Cir. 1987) (same).
94. E.g., Bose Corp. v. Consumers Union of U.S., Inc., 466 U.S. 485, 499 (1984) (“[I]n cases raising First Amendment issues we have repeatedly held that an appellate court has an obligation to ‘make an independent examination of the whole record’ in order to make sure that ‘the judgment does not constitute a forbidden intrusion on the field of free expression.'”) (quoting New York Times Co. v. Sullivan, 376 U.S. 254, 285 (1964)); Church of Scientology, 823 F.2d at 1320 (applying de novo review “when questions of motive implicate constitutional rights”); United States v. McConney, 728 F.2d 1195, 1203 (9th Cir. 1984) (en banc) (“The predominance of factors favoring de novo review is even more striking when the mixed question implicates constitutional rights.”).
95. See Singh, 984 F.3d at 1148 (“Courts follow a case-by-case approach when choosing a standard of review for mixed questions. If a question is more fact intensive, they typically review the question with deference; if it is more legal, they typically review it de novo.”); Kinslow, 105 F.3d at 557 (same).
96. See 583 U.S. at 396.
97. See 728 F.2d at 1202–04 (noting Judge Norris delivered Part II of the court’s opinion, joined by Judges Fletcher, Nelson, and Canby, as inferred from the syllabus and their absence as concurring in or writing the opinions of the other members of the en banc court).
98. Id. at 1202 (internal quotation marks and citations omitted).
99. Id. at 1203 (emphasis added).
100. Am. Int’l Trading Corp. v. Petroleos Mexicanos, 835 F.2d 536, 539 (5th Cir. 1987) (emphasis added) (citation omitted).
101. E.g., Uzdavines v. Weeks Marine, Inc., 418 F.3d 138, 143 (2d Cir. 2005) (reviewing “mixed questions of law and fact either de novo or under the clearly erroneous standard depending on whether the question is predominantly legal or factual”); In re Computer Eng’g Assocs., Inc., 337 F.3d 38, 45 (1st Cir. 2003) (“We review . . . mixed questions somewhere on a sliding scale between de novo and clear error review depending on how fact dominated the question.”); Charter Communications, Inc. v. County of Santa Clara, 304 F.3d 927, 930 (9th Cir. 2002) (“[T]o the extent that a mixed question presents an ‘essentially’ factual inquiry, then review is for clear error.”); Anderson v. Comm’r, 62 F.3d 1266, 1270 (10th Cir. 1995) (“We review mixed questions of law and fact either under the clearly erroneous standard or de novo, depending on whether the mixed question is primarily factual or legal.”).
102. Stilz v. United States, 269 U.S. 144, 147–48 (1925).
103. First Nat. Bank v. City of Hartford, 273 U.S. 548, 552 (1927).
104. Tex-Penn Oil Co., 300 U.S. at 491.
105. Dobson v. Comm’r, 320 U.S. 489, 501 (1943).
106. Miller v. Fenton, 474 U.S. 104, 113–14 (1985) (citation omitted).
107. Id. at 114.
108. Id. at 113.
109. Salve Regina Coll. v. Russell, 499 U.S. 225, 233 (1991) (citation omitted).
110. Wright v. West, 505 U.S. 277, 309 (1992) (O’Connor, J., concurring) (citation omitted).
111. United States v. Gaudin, 515 U.S. 506, 512 (1995).
112. 469 U.S. 412, 428 (1985). Arguably, the Court was moving toward the predominance approach as early as Duberstein in 1960, where it recognized that an issue of intent was “essentially factual, subject to the clearly-erroneous rule.” Pullman-Standard, 456 U.S. at 288 (emphasis added) (citing Duberstein, 363 U.S. at 286).
113. Wainwright, 469 U.S. at 429 (citation omitted).
114. Id. (emphasis added).
115. Id. at 430.
116. 28 U.S.C. § 2254(e)(1).
117. Cooter & Gell v. Hartmarx Corp., 496 U.S. 384, 401 (1990). Rule 11 of the Federal Rules of Civil Procedure authorizes a district court to impose sanctions on an attorney who fails to abide by requirements intended to prevent frivolous litigation. Fed. R. Civ. P. 11(c).
118. Id. at 409.
119. Id. at 401.
120. Id. at 402.
121. Id.
122. Lilly v. Virginia, 527 U.S. 116, 148 (1999) (Rehnquist, C.J., concurring) (emphasis added).
123. Brown v. Plata, 563 U.S. 493, 517 (2011) (Rehnquist, C.J., concurring) (emphasis added) (quoting Lilly, 527 U.S. at 148).
124. 583 U.S. at 396.
125. Id. at 387.
126. Id. at 395 (citing this language from the 1985 decision in Fenton, 474 U.S. at 114: “When an ‘issue falls somewhere between a pristine legal standard and a simple historical fact,’ the standard of review often reflects which ‘judicial actor is better positioned’ to make the decision.”).
127. Id. at 396 (emphasis added).
128. Id.
129. Id. at 388.
130. Monasky v. Taglieri, 589 U.S. 68, 83–84 (2020) (emphasis added).
131. Guerrero-Lasprilla, 589 U.S. at 228 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396) (brackets removed).
132. 593 U.S. 1 (2021).
133. 593 U.S. at 24 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
134. See id.
135. 601 U.S. 209 (2024).
136. Wilkinson v. Att’y Gen. United States, No. 21-3166, 2022 WL 4298337, at *2 (3d Cir. Sept. 19, 2022).
137. Wilkinson, 601 U.S. at 217.
138. Id. at 212.
139. Id. at 222.
140. Id. (emphasis added) (brackets removed).
141. Id. at 222 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
142. 145 S. Ct. 728 (2025).
143. Id. at 739 (emphasis added) (quoting U.S. Bank, 583 U.S. at 396).
144. Id. (quoting U.S. Bank, 583 U.S. at 396) (brackets removed).
145. Wilkinson, 601 U.S. at 222 (citation omitted) (brackets removed).
146. One critic of the predominance approach has written, “It cannot be that deciding whether review is de novo or deferential — the single most important factor in determining whether an appeal will succeed — simply requires adding up the facts in dispute and determining whether legal or factual issues predominate.” Randall H. Warner, All Mixed Up About Mixed Questions, 7 J. App. Prac. & Process 101, 109 (2005).
147. See, e.g., Ornealas, 517 U.S. at 698–699 (demonstrating that de novo review of probable cause determinations safeguards the Fourth Amendment by incentivizing police to seek warrants, since a magistrate’s probable-cause determination is subject to less stringent scrutiny than warrantless searches); Ker v. California, 374 U.S. 23, 33 (1963) (emphasizing that appellate courts must independently articulate and enforce constitutional standards, particularly those governing probable cause, to safeguard Fourth Amendment protections, rather than deferring entirely to trial court determinations).
148. See, e.g., Elberg v. Mobil Oil Corp., 967 F.2d 1146, 1149 (7th Cir. 1992) (stating that “[a] determination that particular facts constitute negligence involves a mixed question of law and fact that is reviewed under the clearly erroneous standard” and affirming the jury’s verdict); Miller v. United States, 587 F.2d 991, 994 (9th Cir. 1978) (emphasizing that negligence determinations are mixed questions of law and fact whose ultimate application is reviewed only for clear error and demonstrating how appellate courts accord substantial deference to trial-level negligence findings); see generally Wright & Miller’s Federal Practice & Procedure § 2590 Mixed Questions of Fact and Law–Negligence Cases (3d ed. 2024).