Montana Republicans approved a plan to close their primary elections and adopt a run-off system for the general election.
A closed primary only allows registered party members to vote for that particular party's candidate. For example, only registered Republican party members could vote in the Republican primary.
Supporters of a closed primary says it's a way to strengthen party unity.
Montana Republicans have been struggling with an internal split between conservatives and more moderate members.
Some party members complained Democrats voted for more moderate republican candidates in the June 3 primary.
Despite being adopted by some 200 delegates at the GOP convention, closing the primary is far from a done deal. And there could be a divide in the party over how to accomplish it.
Matthew Monforton is a Republican candidate who says the goal to close Republican primaries is simple.
"Having the open primary statute we have now declared unconstitutional," Monforton explained.
Monforton looks to the first amendment to make his case. In the simplest terms, the constitution allows political parties to "associate" with whomever they want to keep the party's best interest at heart.
"The Republican leadership well knows that the legislature is never going to change the open primary statute," said Monforton.
So we went to the state's top Republican, Will Deschamps. He says he wants to see what the legislature does, and what the governor thinks before suing in federal court.
Monforton thinks that wait and see approach betrays GOP voters, saying, "To achieve closed primaries and restore integrity in our elections is to seek relief in federal court."
Montana Secretary of State Linda McCulloch says similar complaints of crossing lines from both parties have come up before.
"Truly, my gut feeling is that it doesn't happen to any great extent," McCulloch said.
Critics worry closed parties alienate voters. But what about people who don't vote a party line? She thinks that's a problem too.
McCulloch told us, "We have a great many independent voters who legitimately vote one way or another."
She knows it presents a slew of problems, like ballots for third-party candidates. And then there are potential problems at the polls.
"I think it can throw out election into some confusion," she said.
At the end of the day, no one we talked to seemed sure whether the GOP will sue or will wait for the legislature. Either way, it won't be easy.