The term "Citizens United" refers to a landmark Supreme Court case decided in 2010. The case involved the nonprofit organization Citizens United, which sought to air a film criticizing then-Senator Hillary Clinton during the 2008 presidential campaign. The Supreme Court ruled that the government cannot restrict independent political expenditures by corporations and unions, viewing such spending as a form of protected free speech under the First Amendment. This decision significantly changed the landscape of campaign finance in the United States. It allowed for increased spending in elections, leading to the rise of Super PACs, which can raise and spend unlimited amounts of money to influence elections, often without direct coordination with candidates.