The Montana Republican Party’s lawsuit against Montana’s open primary is active. The case was filed on September 8, 2014, and argued that the Republican Party cannot be forced to let members of other parties help choose its nominees for public office or party office.
The case had been diverted for a while because the party had decided the strongest part of its case concerned the law that forced the party to choose party officers in an open primary. However on May 5, 2015, a new law was enacted that says parties no longer need to use the primary to choose party officers. All sides agree that the part of the lawsuit concerning election of party officers is now moot.
But the party is pursuing the other part of the lawsuit, concerning nominations for public office. On June 4 the Republican Party identified the political science experts it will be relying on to show that non-members have been voting in Republican Party primaries. The state will identify its experts on July 14. The case is Ravalli County Republican Central Committee v McCulloch, 6:14cv-58. The state Republican Party is a co-plaintiff, along with ten county parties.