Citizens United v. Federal Election Commission (2010) Definition

A U.S. Supreme Court decision holding that a federal statute that limited independent political expenditures by corporations and unions was unconstitutional under the First Amendment free speech clause. Citizens United overruled Austin v. Michigan State Chamber of Commerce, 494 U.S. 652 (1990) (allowing restrictions on corporate political expenditures) and partially overruled McConnell v. Federal Election Comm'n., 540 U.S. 93 (2003) (allowing certain restrictions on corporate political spending).