Super PACs and independent expenditures emerged from a series of Supreme Court decisions and federal laws that treated election spending as a form of protected speech under the First Amendment. Starting with Buckley v. Valeo in 1976, the Court drew a constitutional line between contributions to candidates (which could be limited to prevent corruption) and independent expenditures that are not coordinated with campaigns (which could not be capped because they were deemed political expression). That distinction created a legal category of “independent” spending that was structurally distinct from direct campaign donations.

Over the next decades, Congress and the FEC built the modern PAC system under the Federal Election Campaign Act, while courts and regulators narrowed what counts as “coordination,” allowing more activity to be treated as independent. By the 2000s, various outside entities—like 527s and some 501(c)(4)s—were already running election ads as long as they avoided explicit coordination or certain “magic words” of express advocacy. This regulatory environment set the stage for a more formal vehicle that could specialize in unlimited independent expenditures.

The decisive shift came in 2010 with Citizens United v. FEC and SpeechNow.org v. FEC. Citizens United held that corporations and unions could spend unlimited amounts on independent expenditures in federal elections, and SpeechNow applied that logic to create committees that only do independent expenditures and therefore can accept unlimited contributions from individuals, corporations, and unions. Those committees became known as super PACs. Because they are legally barred from coordinating with candidates but can otherwise raise and spend without limit, they have become a permanent and dominant feature of federal campaigns.