As he gears up for a potential Senate run, Republican Rep. Matt Rosendale of Montana is sharpening his critique of Mitch McConnell.

That’s a shift from 2018, when Rosendale first ran for Senate. Back then, McConnell held a fundraiser for him and Rosendale suggested he’d support keeping the Kentucky Republican as the party leader when an opponent said he’d vote to replace him.

But now that he’s not the national GOP’s preferred candidate to take on Democratic Sen. Jon Tester, Rosendale has taken to deriding McConnell as a member of “the DC cartel.”

“I believe that Montanans are tired of business as usual and will reject the McConnell-Biden establishment,” Rosendale tweeted on June 27. That’s the day retired Navy SEAL and aerospace company executive Tim Sheehy announced his Senate candidacy after being recruited by the National Republican Senatorial Committee.

Rosendale’s pointed attacks on McConnell stand in contrast to the comments he made in 2018, when he first ran for Senate. Rosendale attended a fundraiser with the Republican leader from Kentucky in October of that year, according to a press release issued by the Montana Democratic Party.

And unlike Al Olszewski, who also sought the Republican nomination for Montana Senate in 2018, Rosendale expressed support for McConnell.

Aashka Varma, a Rosendale aide, did not respond to an email seeking comment.

Rosendale has not announced his Senate candidacy but is widely expected to run. Over the weekend, he attended an event in the western Montana city of Kalispell, hundreds of miles from his district. Rosendale posted a photo on social media that shows the words “U.S. Congress” on his campaign sign covered in black tape.

On Wednesday, Politico reported that Rosendale has hired a nationally known GOP fundraiser and is inching.

Rosendale, a member of the Freedom Caucus, has the support of conservative groups, although the Club for Growth, which spent $1.7 million in support of Rosendale in 2018, has signaled that it is ambivalent about his potential Senate candidacy this time around.

Tester is one of the most vulnerable senators running next year, and unseating him is key to the GOP’s effort to retake the Senate majority.