Republicans typically cry foul when accused of rewriting election laws to benefit their candidates. But as the Montana Legislature debates a new voting bill, even some G.O.P. lawmakers concede that this one appears designed to help them win elections — more precisely, one very important election.
The bill would rewrite the rules for the state’s next U.S. Senate race and only that race. The 2024 fight to oust Senator Jon Tester, a Democrat, is expected to be one of the tightest in the country.
The legislation would shift the contest from a traditional election into a “top two” primary system, making it exceedingly difficult for third parties to reach a general election ballot. Some believe the system would keep the state’s vibrant Libertarian Party from siphoning votes from the Republican nominee.
While supporters of the bill say it makes elections fairer, both Republican and Democratic lawmakers in Helena have claimed that the bill reeks of political interference. Some have chafed at the involvement of Washington operatives, especially allies of Senator Steve Daines. A Montana Republican and head of the National Republican Senatorial Committee, Mr. Daines is leading the party’s campaign to win control of the Senate in 2024.
Brad Molnar, a Republican state senator who opposes the bill, criticized Washington meddling in Montana politics, saying that if national Republicans get involved, “we will lose.” He predicted that the bill would backfire on Republicans if angry Libertarians flock to Democrats. “They will be angry. Why wouldn’t they be? I’m not a libertarian, and I’m angry.”
The bill’s sponsor, State Senator Greg Hertz, said he was trying to ensure that Montana’s senator would win with more than 50 percent of the vote and to also tamp down on parties’ interference with third-party candidates.
Mr. Hertz said he had designed the bill to apply only to the upcoming Senate race because he saw it as a test run. He expected the Legislature to examine expanding the system to congressional, state legislative and other statewide races in the future.
The system would mirror California’s primaries, where all the candidates from all the parties appear on the same ballot, and the top two vote-getters face off in the general election.