HELENA, Mont. — Montana State Auditor Matthew Rosendale won the Republican nomination for U.S. Senate on Tuesday in the race to challenge Democratic incumbent Jon Tester in November.
Rosendale, who has support from deep-pocketed Republican donors who want to deny Tester a third term, defeated three other candidates in the GOP primary.
"This win is just the first lap, and we've got a lot of race in front of us," he said.
The campaign grew heated when former Judge Russ Fagg said Rosendale, 57, would go easy on "illegal immigrants who commit murder." Political committees backing Rosendale hit back with attacks on Fagg's judicial record.
The race between Rosendale and Tester will be under a spotlight. President Donald Trump vowed to make Tester pay for sinking his nominee to lead the U.S. Department of Veterans Affairs.
Trump's remarks prompted a flood of outside money on ads blasting Tester and propping up Rosendale.
Tester, who is seeking his third term, is one of 10 Senate Democrats facing election in states that Trump won in 2016.
Republicans have been gaining ground on Democrats holding federal and statewide offices in every Montana election since 2010. Two years ago, GOP candidates won every statewide race except the governor's office.
Tester, who did not receive a majority of the votes in his election victories in 2006 and 2012, also faces a potential Green Party challenger who could siphon away some Democratic voters. The Montana Democratic Party has sued to try to disqualify the Green Party from the ballot.
The race is on track to be one of the most expensive in Montana's history, with outside groups already pouring in at least $5 million.
Tester has said outside spending would have come whether or not Trump had said the senator "will have a big price to pay" after releasing allegations that Jackson drank on the job and distributed prescription medication.
Some political analysts say Trump's remarks may actually help Tester by galvanizing Democrats to turn out for a non-presidential election when turnout is typically lower.