Republican heavyweight Senator Lindsey Graham told CNN it was vital Mr Mueller was allowed to get on with the job at hand. Most avoided taking a stand. It is not simply a legal ploy when Republicans running interference for President Donald Trump call the FBI "corrupt" or when Trump's lawyer John Dowd calls to shut down the Russian Federation investigation.
A Trump critic and Senator, Jeff Flake said that Trump's recent comment is hinting towards his preparation for firing of Mueller. But Trump already had made clear his growing impatience at the special counsel and his probe.
Republicans strongly cautioned the President and his team to let Mueller do his work.
"Does anyone think this is fair?" "And yet, there is NO COLLUSION!"
The possibility of Trump firing Mueller was raised after his lawyer, John Dowd, said in a statement that the Justice Department should "follow the brilliant and courageous example of..."
In his tweets, Trump reiterated that there had been "no collusion" between his team and Russian Federation and called the probe a "witch hunt".
On Saturday, Trump tweeted that "The Mueller probe should never have been started" - the first time he has mentioned Mueller by name on Twitter. He criticized Comey's and McCabe's character, adding that McCabe supposedly "knew all about the lies and corruption going on at the highest levels of the Federal Bureau of Investigation!"
Any move to oust Mueller would ignite a political firestorm in Washington. Republican and Democratic lawmakers warned Trump to not even think about it. Three of them have pleaded guilty and agreed to assist in Mueller's investigation.
"I think the president's attorney, frankly, does him a disservice when he says that and when he frames the investigation that way", Gowdy said.
"If he tried to do that, that would be the beginning of the end of his presidency, because we're a rule of law nation", Mr Graham said.
Mr Trump had said Mr Mueller would cross a red line with such a step. The "Special Counsel Integrity Act", introduced by Republican Sen.
The response came after Trump's weekend tweetstorm, in which the president once again attacked Mueller's investigation as a "witch hunt".
Representative Adam Schiff, the top Democrat on the House Intelligence Committee, told ABC that firing Mr Mueller "would undoubtedly result in a constitutional crisis".
Their colleague in the House, Trey Gowdy, had this advice for Trump's lawyer: "If you have an innocent client, act like it".
"I've said all along I don't like special prosecutors", Paul said on CNN.
His Senate counterpart, Majority Leader Mitch McConnell, R-Kentucky, has yet to comment on the ordeal. Without McConnell's backing, bipartisan legislation created to protect Mueller from dismissal has far stalled so far in the Senate Judiciary Committee. "Democrats" and "Zero Republicans?"
"Our Republican colleagues, particularly the leadership, have an obligation to our country to stand up now and make it clear that firing Mueller is a red line for our democracy that can not be crossed", he said in a statement. In December, Mother Jones reported on the many GOP lawmakers who have addressed the implications of firing Mueller. Any dismissal of Mueller would have to be carried out by Rosenstein, who has publicly expressed his support for Mueller.
Mr Trump can not directly fire Mr Mueller.
But, far from being put off by the turmoil rocking his administration, Trump appears to be relishing a new chapter of his presidency, as he axes and undermines aides he distrusts and gives his impulsive personality free rein.
Trump's fresh attacks on Mueller immediately renewed speculation that the President would try to dismiss the special counsel, potentially by replacing Attorney General Jeff Sessions, who is recused from any matter relating to the 2016 elections, and replacing him with an ally willing to do his bidding. Mueller has also reportedly subpoenaed Trump's business for Russia-related records.