David Boies (/bɔɪz/; born March 11, 1941) is an American lawyer and chairman of the law firm Boies, Schiller & Flexner.[2] Boies rose to national prominence for three major cases: leading the U.S. federal government's successful prosecution of Microsoft in United States v. Microsoft Corp., his unsuccessful representation of Democratic presidential candidate Al Gore in Bush v. Gore,[3] and for successful representation of the plaintiff in Hollingsworth v. Perry, which invalidated California Proposition 8 banning same-sex marriage. Boies is also known for defending controversial and disreputable clients in the United States, including Theranos, tobacco companies, and Harvey Weinstein.