Sam Callahan

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 Appellate & Supreme Court practice group, Sam has secured major wins at every level of the federal judiciary, including in landmark cases involving the Administrative Procedure Act (APA), constitutional and statutory interpretation, criminal law, antitrust, insurance, voting rights, and maritime law. He also provides strategic counsel to businesses facing high-stakes investigations and executive orders.

At OMB, Sam supervised major 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 cutting-edge regulatory issues like the Supreme Court’s Loper Bright decision, the expansion of 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 has particular expertise on issues of presidential authority, having managed OMB’s legal and policy clearance process for executive orders, and advised on White House initiatives ranging from artificial intelligence to semiconductors to healthcare to 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 National Endowment for the Arts grants panelist.