On April 24, the Montana Republican Party and some county Republican Parties filed this reply brief in the U.S. Supreme Court. The briefs are now all submitted, in both this case and the Hawaii Democratic Party case. Probably the U.S. Supreme Court will soon set a conference date for both cases. Both cases challenge open primaries. In both cases, the lower courts said the parties haven’t proved that open primaries injure them. In both cases, the major parties argue that they are harmed by never knowing which voters are helping choose their nominees. Unlike the rules in some open primary states, in Hawaii and Montana the voter’s choice of which party primary to choose is secret.