Why some Republican-led states are limiting who can vote in party primaries

States across the country have in recent years opened up their primary elections, making them nonpartisan or allowing independent or unaffiliated voters to cast ballots in party primaries.

Some Republican-led states are moving in the opposite direction.

GOP lawmakers in these states are trying to restrict who can participate in primaries, in an effort to have more ideological purity among their nominees.

Take Louisiana. For years the state has had nonpartisan primaries, in which all candidates regardless of party appear on the same ballot.

Robert Hogan, a political science professor at Louisiana State University, says that system has been very popular with voters and has been lauded by election reformers nationwide.

But the GOP has recently soured on it. In particular, new Republican Gov. Jeff Landry has called the state’s nonpartisan primaries a “relic of the past.”

In a speech at the beginning of a special legislative session this year, he told lawmakers that a closed primary system — which only allows registered members of a party to vote in that party’s primary — would result “in a stronger, more unified team of elected leaders” in the state.

“Every voting-aged citizen in Louisiana may or may not join the political party of his or her choosing,” he said. “If you do choose to join a political party, it is only fair and right that you have the ability to select your party’s candidates for office, without the interference of another party.”

At Landry’s urging, lawmakers in Louisiana voted to replace its nonpartisan primary system with certain closed primaries. Starting in 2026, there will be closed primaries for congressional elections, as well as the state Supreme Court and some other elected offices.

“I think a lot of people will not say it out loud," Hogan said, "but I think the motivating force is basically a desire to create a system that will produce winners that are more ideologically pure."

He said Republicans these days want a system that weeds out candidates who aren’t conservative enough — or what they call "RINOs," short for “Republicans in Name Only.”

“And the poster child for this issue is Bill Cassidy,” Hogan said.

Republican Sen. Bill Cassidy broke with most of his party in voting to convict Donald Trump in his impeachment trial for his involvement in efforts to overturn the 2020 election. Cassidy's vote rankled many Republicans back home.

“They don't like him for those reasons,” Hogan said. “And they know that he is somebody who does appeal to Democrats and does appeal to moderate voters in the state. And if you can create a system where you won't elect those sorts of people, then that's what they want.”

Wyoming curbs 'crossover voting'

In Wyoming, lawmakers last year passed rules further limiting participation in the state’s already-closed primary elections.

Jennifer Green is a registered Republican in Wyoming, even though she is not a conservative. She said the state’s closed primaries leave voters with few choices in a place where the GOP sweeps general elections.

“To have a voice in politics, you kind of need to be a Republican,” she told NPR.

Green said this strategy has allowed her to weigh in on some pivotal primary races. For example, when former Congresswoman Liz Cheney was up for reelection in 2022, Green said she wanted to be sure to vote for her.

“I despise Liz Cheney, her politics, and we disagree on just about everything,” she said. “But in the primaries, I voted for her because she was right on the Jan. 6 hearings and she will go down [on] the right side of history.”

Some Republicans in the state argue many non-GOP voters weighed in on that primary. Wyoming Secretary of State Chuck Gray, a Republican, said voters took advantage of a law that allows voters to register on Election Day.

“I mean, this was a real problem,” he told NPR. “Individuals switching into the primary on the day of the election and then switching back on the way out of the polls — it was very problematic.”

Even though Cheney lost her race despite this alleged help from non-conservatives, Wyoming Republicans sought to outlaw party-switching close to an election, to limit what is often referred to as “crossover voting.” Last year lawmakers passed legislation prohibiting voters from making any changes to their party affiliation up to three months before an election.

Gray said that, in general, non-party members shouldn’t vote in party primary elections.

“It dilutes our primary system, he said. “It creates incentives for people who don't share a party's values to nonetheless prevent voters of that party from electing a candidate that represents the party's platform.”

The Republican moves go against an overarching trend

Along with Louisiana and Wyoming, Republicans in other states — including Colorado, Tennessee and Texas — have been pushing new limits on party primaries, including excluding independent and unaffiliated voters.

That's even though most of the country has been moving in the opposite direction, said Nick Troiano, the founding executive director of Unite America, a philanthropic venture fund that invests in nonpartisan electoral reforms.

“Overall, the overarching trend over the last decade is a story of states opening rather than closing their primaries,” he said.

Troiano said more states are making room for independent and unaffiliated voters in primaries because they are a growing part of the electorate. And he said states moving the other way are doing so for ideological reasons.

“Moving towards a more closed system is weaponizing the election process to impose purity tests on partisanship and ideology,” Troiano said.

Concerns about more extreme candidates

In Louisiana, Democratic state Sen. Jay Luneau said he’s worried the changes to some of Louisiana’s primary elections will make the state’s politics more extreme.

“It's going to push out, unfortunately, I believe, a lot of those people who are in the middle, which I think is desperately what we need in this state, in this country, is to get back to the middle where we were before we went to all of these extremes,” he said.

Studies suggest there is evidence that open and nonpartisan elections do have some effect moderating candidates in a campaign because they are structurally forced to appeal to a wider range of voters. However, experts say broader reforms are needed to make sure more moderate candidates choose to run in the first place.

Troiano said the move to close primaries is ultimately politically shortsighted.

“The rational thing for a party to do when a growing market share of voters are leaving both political parties to become independents is to open their nominating process to welcome a broader swath of the electorate and to build support for their ideas and for their candidates,” he said.

He said while there could be a long-term electoral cost for the GOP, in the short term this is expected to lead to what Republicans want: candidates who are more partisan and won’t do things like vote to impeach Trump.