After Sen. Lisa Murkowski said she was "disturbed" by Senate Majority Leader Mitch McConnell’s approach to President Trump's impeachment, presidential historian Doug Wead said it proved she's an establishment Republican.

“I think this is Senator Murkowski signaling who she is -- that she’s an establishment Republican... the powerful lobbies have to make sure she’s still there in place and she still is,” Wead told "America's Newsroom."

Murkowski, R-Alaska, a high-profile moderate who has found herself in the middle of a highly politicized impeachment process, said in a recent interview that she was "disturbed" by McConnell's recent comments vowing cooperation with the White House.

MODERATE GOP SEN. MURKOWSKI ‘DISTURBED’ BY MCCONNELL’S IMPEACHMENT COMMENTS

While Murkowski stressed the need for a "full and fair process," McConnell, R-Ky., told Fox News' Sean Hannity earlier this month he will be "coordinating" with the White House and that "there will be no difference between the president's position and our position as to how to handle this."

"When I heard that, I was disturbed,” Murkowski told KTUU in an interview that aired Tuesday evening. “To me, it means that we have to take that step back from being hand in glove with the defense, and so I heard what Leader McConnell had said, I happened to think that that has further confused the process."

REPUBLICANS FUME OVER DEM THREAT OF NEW IMPEACHMENT ARTICLES: 'TIME TO CUT THEM OFF'

McConnell has defended his handling of the process, maintaining that the House and Senate -- not to mention the two major political parties -- have been at an "impasse" with Pelosi holding onto the articles of impeachment, apparently in hopes of extracting favorable terms for a trial.

The Kentucky Republican also has responded to criticism that he's too aligned with Trump. Earlier this week on "Fox & Friends," he urged lawmakers to quit the "charade" that senators were supposed to be impartial and apolitical about impeachment, arguing it's clearly a "political" exercise.

Murkowski's comments, though, are sure to fuel speculation over whether she and a handful of other moderate GOP senators could potentially break ranks on impeachment.

CLICK HERE TO GET THE FOX NEWS APP

"I don’t think [impeachment is] going anywhere and it's certainly not outrageous for Senator McConnell to press this as a Republican because the impeachment was 100 percent, 100 percent Democratic," Wead said. None of the Republicans in the House voted in favor of impeaching Trump.

Fox News’ Ronn Blitzer and Molly Line contributed to this report.