Jack Heyburn is an associate in the New York office of Gibson, Dunn & Crutcher. He previously practiced in the firm’s Washington, D.C. office from 2019 to 2021. Jack is a member of the firm’s Litigation, Appellate and Constitutional Law, and Administrative and Regulatory practice groups.

He has represented clients in a wide range of high-stakes appellate, administrative law, and commercial litigation matters. His appellate practice has included cases in the Supreme Court of the United States, the U.S. Courts of Appeals for the Second, Third, Fourth, Fifth, Tenth, Eleventh, and D.C. Circuits, as well as numerous state courts of appeals. In addition to trying cases on appeal, Jack has extensive experience at all stages of trial-level litigation—from winning dismissals of lawsuits outright to taking cases to trial.

Representative matters include:

Constitutional and appellate litigation. In his appellate practice, Jack has grappled with some of the most important issues of constitutional law, including the separation of powers and citizenship, and handled appeals with over $1 billion at stake. Recent highlights include:

• Owens v. Turkiye Halk Bankasi A.S., No. 21-610 (2d Cir.). Represented a group of nearly 1,000 victims of state-sponsored terrorism in the Second Circuit in an action to enforce over $1 billion in judgments against the Islamic Republic of Iran.
• Fitisemanu v. United States, No. 21-1394 (U.S.). Defended on appeal in the Tenth Circuit and the Supreme Court a district court decision striking down 8 U.S.C. § 1408(1)—which denies citizenship to persons born in American Samoa—as unconstitutional under the Fourteenth Amendment’s Citizenship Clause.
• Dep’t of Homeland Security v. Regents of the Univ. of Cal., No. 18-587 (U.S.). Represented a group of Dreamers before the Supreme Court in a successful APA challenge to the federal government’s 2017 rescission of the DACA program.
• Secured a complete dismissal of a high-profile COVID-19-safety class action in the Eastern District of New York, and successfully defended the dismissal on appeal in the Second Circuit.
• Successfully defended on appeal in the Illinois Appellate Court a summary judgment ruling that completely dismissed all fraud and breach of fiduciary duty claims against his client, an international law firm.
• Jack also maintains an active pro bono practice and has filed numerous amicus briefs in the Supreme Court and the U.S. Courts of Appeals.

Complex trial-level litigation. Jack also represents clients in a wide array of complex trial-level litigation matters. These cases run the gambit from those involving federal securities fraud to legal malpractice claims, civil fraud, and sports law. Recent highlights include:

• In re: Aqueous Film-Forming Foams Prods. Liab. Litig., MDL No. 2:18-mn-2873. Representing an American manufacturing company in a multidistrict products-liability litigation that includes over 2,500 individual cases.
• Baffert v. Churchill Downs Incorporated, No. 3:22-cv-123 (W.D. Ky.). Successfully defended Churchill Downs Incorporated against a lawsuit brought by the well-known horse trainer, Bob Baffert, including a full denial of Baffert’s motion for a preliminary injunction and a complete dismissal of his lawsuit prior to discovery.
• Tilton v. MBIA, Inc., Index No. 68880/2015 (Sup. Ct. Westchester Cty.). Represented an investment firm and its founder in a two-week jury trial involving complex issues relating to Collateralized Loan Obligations.
• Jack’s recent representations also include defending a regional bank against a securities fraud class action, defending an international law firm against legal malpractice claims, and representing a small business in a challenge to state occupational licensing laws.

Administrative law. Jack represents clients in a variety of administrative law matters, including those involving the Environmental Protection Agency, the Department of Transportation, the Food and Drug Administration, and the Consumer Financial Protection Bureau, among others. Recent highlights include:

• Union of Concerned Scientists v. Nat’l Highway Traffic Safety Admin., No. 19-1230 (D.C. Cir.). Represented a coalition of major auto manufacturers in several consolidated challenges in the D.C. Circuit to a joint rulemaking by the National Highway Traffic Safety Administration and the Environmental Protection Agency regarding fuel economy standards and tailpipe greenhouse gas emissions.
• Representing a consumer-products company in high-stakes litigation against the FDA regarding the approval of products that are essential to the company’s business.
• Defended on appeal in the D.C. Circuit an order from the Federal Election Commission declining to pursue certain campaign finance claims against a presidential campaign.
• Provided strategic advice to a client in the banking industry facing the threat of enforcement action from the Consumer Financial Protection Bureau.

Prior to joining the firm, Jack served as a law clerk to the Honorable Marjorie O. Rendell, U.S. Court of Appeals for the Third Circuit (2018–2019).

Jack graduated cum laude from the University of Pennsylvania Law School in 2018. At Penn, he was a member of the Supreme Court Clinic, led by now-Judge Stephanos Bibas of the U.S. Court of Appeals for the Third Circuit. He was also the winner of the law school’s annual moot court competition, the Edwin R. Keedy Cup. And he was a member of the editorial board of the University of Pennsylvania Journal of Constitutional Law.

Jack has also engaged in legal writing outside of his practice. His scholarship on the drafting of the Constitution, Gouverneur Morris and James Wilson at the Constitutional Convention, 20 U. Pa. J. Const. L. 171 (2017), has been cited in numerous academic journals and books.

Prior to law school, Jack served on the legislative staff for United States Senator Mitch McConnell (2013–2015). In 2013, Jack graduated with a Bachelor of Arts in History from Vanderbilt University.

Jack is admitted to practice in New York and the District of Columbia. He is also admitted to practice in the United States Courts of Appeals for the Third, Fifth, Ninth, Tenth, and Eleventh Circuits and the United States District Court for the District of Columbia.