The Montana Republican Party is also a plaintiff in the lawsuit, but does is not taking sides in the presidential nomination process or the primary, said Jeff Essmann, party chairman. The state party joined the lawsuit in order to have its first Amendment right of political association recognized and enforced.

Monforton’s opinions are his, not the party’s, Essmann said.

Calls to the Trump campaign in Montana were not returned by Wednesday evening.

When Republicans filed their request to the Supreme Court on Friday, people wrote it off as a long shot. Now that the state is being forced to respond, Monforton said he believes his party’s chances are improving.

“Montana’s open primary system permits any elector to anonymously vote for party nominees,” Monforton argues in the lawsuit. “The state is thereby violating the party’s right to identify its members, as well as its right to exclude nonmembers.”