WASHINGTON -- Members of congress have a message for President Trump: Don't antagonize special counsel Robert Mueller, or you could regret it.

"It would prompt a firestorm," said Sen. Richard Blumenthal (D-Conn.).

Members of both parties are warning the president not to mess with Mueller.

"Firing Bob Mueller without cause is an attack on the rule of law," said Sen. Ron Wyden (D-Ore.).

Special Counsel Robert Mueller. CBS News

"It sort of looks paranoid to me," said Rep. Michael McCaul (R-Texas), who chairs the House Homeland Security Committee. "If he fired Bob Mueller, I think you'd see a tremendous backlash response from both Democrats but also House Republicans."

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Respect for Mueller runs deep on Capitol Hill, especially among Republicans.

He was President George W. Bush's pick for FBI director, and served throughout the Bush presidency.

Trump Mueller leverage

House Speaker Paul Ryan has had the same message for Mr. Trump since Mueller was tapped as special counsel in May: "I think the best advice would be to let Robert Mueller do his job."

Republicans were also stunned by the president's slam on their former Senate colleague Jeff Sessions, who is now attorney general.

"Jeff Sessions takes the job, gets into the job, recuses himself. I then have -- which, frankly I think is very unfair to the president," Mr. Trump told The New York Times.

Dickerson on Trump

Iowa Republican Sen. Chuck Grassley says Sessions was right to recuse himself.

"The attorney general can't be a wingman for a president. He's got to be very independent," Grassley said.

As for those attempts to dig up dirt on Mueller or his staff, Florida Sen. Marco Rubio says good luck.

"I don't think it's going to influence Bob Mueller's work one way or another," Rubio said. "I'm pretty confident just knowing him and knowing the way he conducts himself he doesn't wake up in the morning and read those things and have them impact his ability to do his job. He's going to do his job."

Some Republican aides on Friday praised the choice for new White House communications director Anthony Scaramucci, emphasizing his poise and charisma. Others complained that Scaramucci has no experience with communications planning and strategy -- something they think this White House badly needs.