California's "jungle primary," formally the top-two system, was marketed as a reform to curb partisanship, empower moderates, and boost voter turnout. Adopted via Proposition 14 in 2010, it allows all candidates to compete on a single primary ballot, with the top two advancing to the general election regardless of party.

The U.S. Supreme Court's January 14, 2026, ruling in Bost v. Illinois State Board of Elections (No. 24-568) is a 7-2 decision affirming that political candidates have Article III standing to challenge state election laws on vote counting in federal races.