Texas Republicans are pushing to overhaul the state’s open primary election system, seeking to limit participation in GOP primaries to voters who formally register as Republicans, a move that has sparked legal challenges and concerns from voting rights advocates.

Texas currently operates under an open primary system, allowing registered voters to choose which party’s primary to vote in on election day without declaring a party affiliation in advance. The Texas Republican Party argues that system allows non-Republicans to influence GOP nominations.

In September, the state party filed a federal lawsuit seeking to block enforcement of Texas election laws that require open primaries. The lawsuit argues the system violates the party’s First Amendment right to freedom of association by forcing Republicans to allow nonmembers to participate in selecting their nominees.

Attorney General Ken Paxton has joined the effort, filing court motions supporting the party’s position. The case names Texas Secretary of State Jane Nelson as a defendant, though her office has opposed the lawsuit, arguing that any change to the primary system should be made by the Legislature, not the courts.

Republican leaders say the push is driven by concerns about “crossover voting,” in which voters affiliated with other parties participate in GOP primaries to sway outcomes. Party officials point to a 2024 Republican primary ballot proposition in which a majority of GOP voters supported restricting participation to registered Republicans.

“If Republicans are going to choose Republican candidates, those voters should be Republicans,” party officials have argued in court filings.

Voting rights advocates and election officials warn the proposal could significantly alter voter participation in Texas, where the GOP primary often determines the eventual officeholder in statewide and legislative races.

Critics say requiring voters to register with a party could discourage participation among independents and voters who prefer not to affiliate politically. Texas does not currently have a system for party-based voter registration, and election administrators say implementing one would require major changes to election infrastructure.

Opponents also warn the change could reduce turnout and push primary contests toward more ideologically extreme outcomes by limiting participation to the most engaged party activists.

The lawsuit is being heard in federal court in Amarillo, a venue frequently used in conservative legal challenges. Even if Republicans prevail, election officials say the timeline would make it difficult to implement changes before the March 2026 primaries, meaning any shift would likely take effect in later election cycles.

Texas is one of several states where parties have debated closing primaries amid broader national arguments over voter access, election security and party control. While some states operate closed primaries, others maintain open or semi-open systems designed to encourage broader participation.

The outcome of the Texas case could have lasting implications for how elections are conducted in the nation’s second-largest state and could influence similar efforts elsewhere.