GOP Rep. Matt Rosendale of Montana, a member of the hard right House Freedom Caucus, announced Friday he's running for Senate.

"Today, I'm asking for your support to run for the United States Senate," he said in a video posted on X.

Rosendale is the second Republican to jump into the race to unseat incumbent Democratic Sen. Jon Tester. He'll face off against Tim Sheehy, a veteran and wealthy businessman who announced his candidacy last June. Sheehy is backed by National Republican Senatorial Committee Chairman Steve Daines and Senate Minority Leader Mitch McConnell.

Daines tried to clear the Republican field for Sheehy to challenge Tester, who first won the Senate seat in 2007 and is seeking reelection to a fourth term.

Montana, a red state that Trump won twice, is a top target for Republicans hoping to take control of the Senate in November. They only need to flip two seats, and if a Republican wins the White House, they'd only need one.

National Republicans see Sheehy as having more general election appeal than Rosendale, who was one of the small group of House Republicans who voted to oust Speaker Kevin McCarthy.

Daines told CBS News in an interview last month he hoped Rosendale would seek reelection to his House seat.

"I think primaries generally are not always helpful. And so I think it'd be better if Matt Rosendale would stay in the House and build seniority."

In the lead up to Rosendale's announcement, House Speaker Mike Johnson was expected to endorse him before he abruptly backpedaled.

In his video on X, Rosendale said, "Speaker Johnson and I have always had a great relationship. I am thankful for his continued support." He added, "Mitch McConnell and the D.C. Cartel are terrified about me going to the U.S. Senate. They know they can't control me; they know I won't vote for McConnell as Leader. But they are fixin' to find out that in Montana, we don't take orders from Washington; we send orders to Washington!"