Rep. Matt Rosendale Launches Senate Run in Montana, Setting Up GOP Primary Battle

Hoping to unseat Democrat Jon Tester, he’s ‘running against the Washington establishment, against Joe Biden and Mitch McConnell.’

Rep. Matt Rosendale (R-Mont.) speaks at a news conference outside the U.S. Capitol in Washington on July 25, 2023. Anna Moneymaker/Getty Images

Rep. Matt Rosendale (R-Mont.) announced on Feb. 9 that he is running for the Senate this year, setting up a primary battle for vulnerable Democrat Sen. Jon Tester’s seat.

In a video posted on X, formerly Twitter, Mr. Rosendale said he is running as a Washington outsider—despite already being a member of Congress.

“I’m running against the Washington establishment, against [President] Joe Biden and [Senate Minority Leader] Mitch McConnell,” he declared.

“The Washington insiders are causing an invasion at our southern border, enriching their friends with the Green New Deal, allowing China to spy and emerge as the global superpower,” he said. “All the while retaining power for themselves and ignoring We the People.”

Mr. Rosendale touted himself as a staunch ally of former President Donald Trump.

“I voted in support of President Trump’s agenda every single time,” he said.

Mr. Rosendale went so far as to cite him objecting to the 2020 election results on Jan. 6, 2021, when Trump supporters breached the U.S. Capitol.

Mr. Rosendale blasted his main opponent, wealthy businessman Tim Sheehy, for donating to former U.N. Ambassador and South Carolina Gov. Nikki Haley’s political action committee in March 2021, almost two years before she launched her campaign for president. Mr. Sheehy has said he “100 percent” supports President Trump.

At the end of the day, Mr. Rosendale said he is running against Mr. McConnell and would not support him as Senate GOP leader.

Among Mr. Rosendale’s supporters are Sen. Mike Lee (R-Utah), Rep. Matt Gaetz (R-Fla.), Montana Senate President Jason Ellsworth, Montana House Speaker Matt Regier, pro-Trump podcaster Steve Bannon and Gun Owners of America (GOA).

“I’m 100 percent sure Mitch McConnell has a candidate in the Montana GOP Primary. And 1000 percent sure it isn’t Matt Rosendale. Fire Mitch. Support Rosendale,” posted Mr. Gaetz on X.

“From his time serving in the State Legislature to statewide elected office as Auditor and now Congressman, Matt Rosendale has never wavered in leading with his conservative principles. He has earned Montanans’ trust with his dedication, unmatched energy and work ethic, and commitment to the people of our state,” said Mr. Ellsworth in a statement.

“Matt Rosendale is the Gun Owners’ choice and the only Montana Senate candidate who won’t hesitate to stand up for your God-given right to defend yourself against a tyrannical government,” said GOA Chairman Tim Macy in a statement.

Mr. Lee posted on X that Mr. Rosendale “has a proven record of fighting the DC swamp & scars to prove it.”

Meanwhile, Mr. Sheehy has been endorsed by Montana Gov. Greg Gianforte, a dozen senators, including Senate GOP Conference Chairman John Barrasso (R-Wyo.), and the National Republican Senatorial Committee, which is the fundraising arm of the Senate GOP.

This is Mr. Rosendale’s second time running for a Senate seat. In 2018 he lost by almost 4 percentage points to Mr. Tester, who is running for reelection.

Mr. Rosendale was elected to the House in 2020. He was one of eight Republicans who joined Democrats in ousting House Speaker Kevin McCarthy (R-Calif.) last September.

“He violated our trust when he passed the budget ceiling deal with more Democrats than he did Republicans after—keep in mind—the Republicans got together and put together an incredible package,” Mr. Rosendale told NBC Montana.

He said his decision to vote to strip Mr. McCarthy of the gavel was not made lightly.

“My initial reaction is it’s unfortunate. I do not take any great pleasure in going through this process, but it was something that had to be done,” he said.

The GOP Senate primary is on June 4.