Sam Callahan | People | Arnold & Porter

Sam Callahan, former Senior Counsel of the White House Office of Management and Budget (OMB), helps businesses and organizations navigate regulatory threats and successfully challenge government action in court.

A member of the firm’s administrative law and appellate teams, Sam has secured major wins at every level of the federal judiciary, including in precedent-setting cases involving the Administrative Procedure Act (APA), constitutional and statutory interpretation, voting rights, and federal appropriations law. He also provides strategic counsel to businesses facing high-stakes federal investigations, negotiations, and executive orders. Sam is a co-founder and editor of the firm’s Major Questions blog and frequently presents on administrative law and regulatory litigation topics.

At OMB, Sam supervised APA litigation and was a principal legal advisor to the Office of Information and Regulatory Affairs (OIRA), the hub of regulatory activity across the Executive Branch. He helped develop government-wide strategy on cross-cutting regulatory issues like the Supreme Court’s Loper Bright decision, the major questions doctrine, and the Congressional Review Act. Sam also advised senior White House and agency officials on issues of fiscal and budgetary policy, government contracting, and congressional oversight. Sam developed particular expertise on issues of presidential authority, managing OMB’s executive orders process, and guiding White House initiatives on artificial intelligence, semiconductors, healthcare, and environmental protection.

Sam clerked for Judge Paul V. Niemeyer of the U.S. Court of Appeals for the Fourth Circuit and Judge Christopher R. Cooper of the U.S. District Court for the District of Columbia. He graduated magna cum laude from Harvard Law School, where he was an Executive Editor of the Harvard Law Review, and received degrees in economics and trumpet performance from Indiana University. He remains active in music as a member of the Capital City Symphony and as a grants panelist for the National Endowment for the Arts.

Focus Areas

Experience

Major nonprofit organizations in advising on litigation strategy and novel regulatory issues related to threatened revocations of tax-exempt status under section 501(c)(3) of the Internal Revenue Code.
Pharmaceutical manufacturers and trade associations on numerous constitutional, statutory, and administrative law issues, including federal government efforts to impose most-favored-nation (MFN) prescription drug pricing.
AT&T in several state regulatory proceedings.
Public media broadcasting stations on Federal Communications Commission compliance and policy issues.
Foreign-aid grantees and contractors in litigation challenging funding freezes by the U.S. Agency for International Development (USAID) and Department of State.

National trade association in successful APA challenge to novel emissions and fuel-consumption regulations imposed on trailers. Persuaded the D.C. Circuit to stay enforcement and vacate the agencies’ rules as exceeding their statutory authority. Truck Trailer Manufacturers Ass’n v. EPA, 17 F.4th 1198 (D.C. Cir. 2021).
Property developer in successful appeal regarding an agency’s application of historic preservation law to a major redevelopment project. D.C. Preservation League v. Mayor’s Agent for Historic Preservation, 236 A.3d 373 (D.C. 2020).
Immigrant rights organizations at the U.S. Supreme Court in a successful APA challenge to the attempted addition of a citizenship question to 2020 Census. Department of Commerce v. New York, 139 S. Ct. 2551 (2019).

Group of over 50 companies in Third Circuit appeal involving a significant CERCLA settlement related to the Passaic River in New Jersey.
Honeywell in litigation raising complex preemption and statutory interpretation questions related to alleged radioactive emissions from the Metropolis Works uranium conversion facility.
Member of Congress in federal assault prosecution presenting issues of legislative immunity and other constitutional defenses.
Raytheon Co. in securing affirmance of dismissal of employee’s False Claims Act retaliation claims stemming from national-security-related investigation and termination. United States ex rel. Johnson v. Raytheon, 93 F.4th 776 (5th Cir. 2024).
North Carolina voters in convincing the U.S. Supreme Court to reject the “independent state legislature” theory. Moore v. Harper, 143 S. Ct. 2065 (2023).

Insurer in obtaining reversal of an $18 million judgment in the Third Circuit against an affiliate of AIG arising from faulty workmanship in the fracking of natural gas wells. American Home Assurance Co. v. Superior Well Services, Inc., 75 F.4th 184 (3d Cir. 2023).
Public health researcher in defamation action based on statements criticizing a company’s scientific research and marketing. Successfully briefed and argued Second Circuit appeal, securing dismissal on the basis that the statements were protected opinions. Valley Electronics AG v. Polis, 2022 WL 893674 (2d Cir. Mar. 28, 2022).
Healthcare company in securing affirmance of dismissal of a Clayton Act suit for failure to establish antitrust standing. Ekbatani v. Community Care Health Network, LLC, 2022 WL 31793 (11th Cir. 2022).
Former Members of Congress and House General Counsels as amici curiae in several cases at the U.S. Supreme Court and federal appellate courts involving the separation of powers, including Trump v. Mazars USA, LLP, 591 U.S. 848 (2020).
North Carolina voters and organizations in successful voting rights litigation to redraw North Carolina’s state legislative maps under state law. Common Cause v. Lewis, 2019 WL 4569584 (N.C. Super. Sep. 03, 2019).
Individual serving life sentence in briefing and arguing successful Fourth Circuit appeal asserting ineffective assistance of trial counsel. Convinced Fourth Circuit to unanimously vacate the dismissal of a § 2255 petition and to order evidentiary hearing regarding failure to seek suppression of un-Mirandized statements. United States v. Pressley, 990 F.3d 383 (4th Cir. 2021). On remand, first-chaired evidentiary hearing, persuaded district court to vacate client’s convictions and life sentence, negotiated favorable plea agreement, and secured client’s release.
Cruise lines in successfully defending dozens of lawsuits, including several putative class actions, arising from COVID-19 pandemic. Developed successful strategy for moving to strike jury demands, removing to federal courts, and enforcing federal statutes limiting liability in cases presenting novel issues under maritime law.
Pharmaceutical manufacturers and trade association in numerous cases related to drug pricing and disclosure laws.