A senior Democratic senator says “it would create an extremely dangerous situation” if President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE fires Deputy Attorney General Rod Rosenstein Rod RosensteinDOJ kept investigators from completing probe of Trump ties to Russia: report Five takeaways from final Senate Intel Russia report FBI officials hid copies of Russia probe documents fearing Trump interference: book MORE, calling on Congress to pass legislation to protect special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE.

“We’ve already passed the point where the president is trying to interfere with the Mueller investigation. He’s already said things, done things that’s inappropriate for the president of the United States,” Sen. Ben Cardin Benjamin (Ben) Louis CardinPelosi hopeful COVID-19 relief talks resume 'soon' Congress must finish work on popular conservation bill before time runs out PPP application window closes after coronavirus talks deadlock MORE (D-Md.) said in an interview with Hill.TV. “If he were to fire Rod Rosenstein, he’s upped the ante dramatically, and it would create an extremely dangerous situation.

Rosenstein, whom Trump has repeatedly attacked in public, is overseeing Mueller’s Russia probe following the recusal of Attorney General Jeff Sessions Jefferson (Jeff) Beauregard SessionsRoy Moore sues Alabama over COVID-19 restrictions GOP set to release controversial Biden report Trump's policies on refugees are as simple as ABCs MORE.

Trump is set to meet with Rosenstein on Thursday — their first in-person, one-on-one since The New York Times reported that the deputy attorney general threatened to wear a wire while talking to the president in a discussion of invoking the 25th Amendment.

“Congress needs to act now to protect the Mueller investigation — we have bipartisan legislation that was approved by the Judiciary Committee. We need to take that up to protect the Mueller investigation,” Cardin said.

— Molly K. Hooper