Whether courts of appeals must apply substantial-evidence review to the Board of Immigration Appeals' determination of whether a given set of undisputed facts constitutes “persecution” under 8 U.S.C. § 1101(a)(42). This involves interpreting the scope of judicial review provided by the Immigration and Nationality Act (INA). Specifically, the Court must determine if such a finding is a "finding of fact" subject to the deferential standard in 8 U.S.C. § 1252(b)(4)(B).

• De novo review should apply because 8 U.S.C. § 1252(b)(4)(B) requires deference only for “findings of fact.”
• The determination of persecution is a “mixed question of law and fact,” and no subparagraph of § 1252(b)(4) explicitly addresses such mixed questions.
• Under *Loper Bright Enterprises v. Raimondo*, de novo review is required in these circumstances.

• The substantial-evidence standard is the correct standard for reviewing the agency's persecution determination.
• The application of the legal standard for persecution to the facts is a finding that should be treated as conclusive unless a reasonable adjudicator would be compelled to conclude otherwise.
• Purely legal questions regarding the appropriate standard of persecution are subject to de novo review, but the application of that standard to the record is not.

• The Court held that 8 U.S.C. § 1252(b)(4)(B) requires courts to review the entirety of the agency's persecution determination—both the underlying factual findings and the application of the INA to those findings—for substantial evidence.
• The Court relied on 8 U.S.C. § 1252(b)(4)(B), which provides that “administrative findings of fact are conclusive unless any reasonable adjudicator would be compelled to conclude to the contrary.”
• The Court invoked *Nasrallah v. Barr* to establish that the language of § 1252(b)(4)(B) prescribes a deferential “substantial-evidence standard.”
• The Court defined substantial evidence, citing *Biestek v. Berryhill*, as “such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.”
• The Court reasoned that *INS v. Elias-Zacarias* previously established that an asylum applicant must show evidence was “so compelling that no reasonable factfinder could fail to find the requisite fear of persecution” to obtain judicial reversal.
• The Court concluded that the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA) codified the *Elias-Zacarias* standard through the addition of 8 U.S.C. § 1252(b)(4).
• The Court rejected the "mixed question" argument, noting that refugee status determinations primarily require critical factual findings and that it would be "anomalous" to review these de novo while deferring to other IJ factfinding under § 1252(b)(4).
• The Court distinguished *Wilkinson v. Garland* and *Guerrero-Lasprilla v. Barr*, explaining that those cases addressed whether a court had jurisdiction to review a question under § 1252(a), not the standard of review to be applied under other provisions of the statute.