By Josie Frost

COLUMBIA, S.C. — The South Carolina Republican Party has filed a federal lawsuit seeking to close the state's Republican primaries, arguing that only registered Republicans should be allowed to choose the party's nominees.

South Carolina has an open primary system, meaning voters do not have to register by political party and can choose which party's primary to vote in during each election. Republican leaders have pushed for years to change that through legislatoin. After those efforts repeatedly stalled, the party is now asking a federal court to intervene.

State GOP Chairman Drew McKissick has called for closed primaries over the last several years, saying Republican voters should be the only ones deciding the party's nominees.

"We would affiliate with people we want to affiliate with when we choose nominees, not be required to allow people to come in who don't affiliate with us to help choose our nominees, which is the current reality," McKissick said.

Earlier this year, the South Carolina Republican Party adopted new rules that would require voters to be registered Republicans to participate in Republican primaries. Independent voters could become registered Republicans when they vote in a Republican primary.

The new rules would also require Republican candidates to have been registered party members for at least 90 days and to have voted in at least two of the three most recent statewide Republican primaries. Candidates who do not meet those requirements would need a waiver from local or state party officials to qualify for the ballot.

While the SCGOP adopted the rule change, it can't be enforced without a change in state law, which the lawsuit is seeking.

"Without partisan voter registration it's impossible for us to limit our primaries to only Republicans or only people who want to affiliate with our party, and so far the legislature has refused to do that," McKissick said. "We haven't been able to get any action, so you know we've had no other alternative other than now go to federal court."

Republican leaders argue the open primary system allows voters from other parties to influence GOP nominations by supporting more moderate candidates or candidates they believe will be easier to defeat in the general election.

Lynn Teague, vice president of the League of Women Voters of South Carolina, said that kind of crossover voting is uncommon and rarely changes election outcomes. She argued that closing primaries would further divide voters.

"Sometimes you decide that your preferred candidate is in one party, and sometimes you decide somebody from another party. This actually does happen, and you should be able to vote that way. That should not be prevented," Teague said.

The South Carolina Democratic Party also opposes closing the state's primaries. Very few voters participate in primaries already, and Executive Director Jay Parmley said closing primaries will only exclude more people.

"Their whole debate is about limiting participation and making sure that only people that agree with them on everything are registered party members, that then they're the only people who gets to participate in this democracy," Parmley said.

The lawsuit argues South Carolina's open primary system violates the Republican Party's constitutional right to freedom of association. If the party prevails, McKissick said the state would have to change its laws to allow some form of closed primary system.

The case has been assigned to Judge Mary Geiger Lewis.

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