Montana's libertarian candidate dropped out of the state's Senate race Wednesday and threw his support behind Republican Matt Rosendale, a move that could cause trouble for incumbent Sen. Jon Tester, D-Mont.
Rick Breckenridge told reporters on a conference call Wednesday that he was upset about an outside attack ad against Rosendale and urged his supporters to cast their ballots for the Republican.
Montana has a one of the highest libertarian populations in the U.S. and the party's members are active in state and national elections. The group has proved difficult for Tester in his prior two elections. The senator's margin of victory in 2006 and 2012 was slimmer than the share of the vote the libertarian candidate received. In 2006, Tester won his first election by one percentage point. That same year, the libertarian candidate took 2.5 percent of the vote. In 2012, the libertarian candidate took 4.5 percent of the vote when Tester won by a margin of 4 percentage points.
The Montana Senate race is currently just outside the margin of error. RealClearPolitics polling average has Tester with a 4.2 percentage point lead over Rosendale.
One factor that could prevent Breckenridge's endorsement from having a decided effect, however, is that some Montanans have already cast their votes with Breckenridge's name on the ballot.
Another factor in the final week will be the president's rally in Bozman on Nov. 3. The president's rallies have proven effective at rallying conservative voters to the ballot box. The day before Trump stumped for Sen. Ted Cruz, R-Texas, voter registration in Texas reached a record high of 15.7 million. Roughly 20,000 people showed up to see the president in Texas.