Montana Republicans were weighing broad changes to how candidates are picked during primary election as the political party's convention headed to a finale Saturday.
The three-day convention in Billings has emerged as the latest staging ground for moderate and conservative Republicans maneuvering for position within the party.
More than 200 delegates were expected to vote on a proposal advanced by conservatives to close primary elections to Democrats and other outside voters.
That comes after conservatives complained that Democrats crossed party lines to bolster the chances of moderate Republicans in some contested races.
State Sen. Jeff Essmann of Billings, who introduced the proposal, said it's an issue of fairness. "It's about the election of Democrats by Democrats, Libertarians by Libertarians and Republicans by Republicans," Essmann said.
Opponents of the idea say it's designed to give conservatives a lock on the party, alienating voters who are needed to win general elections.
Twenty-four states have closed Republican primaries and 19 states have closed Democratic primaries, according to the nonpartisan, Maryland-based group Fairvote.
Proponents among Montana Republicans said the closure of future primaries could be accomplished either through legislative action or a lawsuit.
Another election-related proposal calls for party leaders to endorse candidates more than a month before primaries are held.
Rep. Mike Miller, a Helmville Republican, said the idea equates to an "incumbent protection act" in which leaders would favor those already in office.