Republicans Sue to Close Colorado Primary, Announce SC Lawsuit Plans

Republicans in two states launched coordinated legal challenges to prevent unaffiliated voters from participating in GOP primaries. In Colorado, three Republican candidates filed a lawsuit to bar unaffiliated voters from the June 2026 Republican primary, while in South Carolina, the state Republican Party announced plans for a federal lawsuit to dismantle its open primary system.

In Colorado, candidates Ron Hanks, Scott Bottoms, and David Wilson sued Governor Jared Polis and Secretary of State Jena Griswold, arguing that semi-open primaries violate the 1st and 14th Amendments by diluting party members' votes. The lawsuit targets a state statute created by Proposition 108, a 2016 ballot measure. Griswold said she expects the lawsuit to fail, pointing to a previous federal court ruling against a similar challenge by the Colorado Republican Party. A hearing was set for May 14, 2026.

In South Carolina, the Republican Party announced it would file a federal lawsuit after the June 9 primary elections to mandate partisan voter registration. SCGOP Chair Drew McKissick argued the current open primary system violates the First Amendment right of political parties to determine their own membership. The legal action follows two failed legislative attempts to close primaries, which stalled amid GOP caucus divisions and a threatened gubernatorial veto. Attorney General Alan Wilson and U.S. Rep. Ralph Norman, both gubernatorial candidates, voiced support for the effort.