Attacks on special counsel Robert Mueller’s credibility from some of President Donald Trump’s closest allies have again fallen flat with the U.S. Senate, which is in no rush to advance recently proposed legislation that would shield Mueller from presidential interference.

Senate Republicans have cautioned Trump en masse against moving to fire Mueller or interfere with the investigation in any way. At the same time, though, many have taken Trump at his word—the president said Sunday he is not considering firing Mueller—and have argued that a legislative backstop is unnecessary. But as the investigation intensifies and top Trump campaign officials are indicted, the pro-Trump voices that often influence the president have stepped up their efforts to impugn the Mueller investigation’s credibility.

Questions over whether Trump will interfere with the Mueller probe resurface often, prompting lawmakers to do damage control for the president. Despite the heightened criticisms as of late, senators are still confident that Mueller is up for the job. But legislating the problem away is a bridge too far for some.

“Well, as long as he follows through,” Sen. John Thune (R-S.D.) quipped to The Daily Beast when asked if he takes Trump at his word.

Sen. Jeff Flake (R-AZ), who dedicated his retirement speech on the Senate floor to impugning Trump, said “I don’t know how to answer that.”

Still, Flake does not believe a legislative backstop is necessary.

“I don’t think it’s needed. I don’t think he’s going to do it,” Flake told The Daily Beast. “I’ve been troubled by the efforts to discredit the investigation, coming from a lot of sources.”

Two pieces of legislation were introduced in August, just before Congress left Washington for the summer, ostensibly as a way to put a spotlight on the possibility that Trump moves to fire Mueller while Congress was away. At the time, Trump was floating the idea of firing the special counsel for looking into his personal finances as part of its investigation into Russia’s election meddling and possible collusion between Trump campaign associates and Russian operatives.

One of the legislative backstops, proposed by Sens. Chris Coons (D-DE) and Thom Tillis (R-N.C.), would allow a special counsel to challenge his or her firing in front of a panel of three federal judges who would the decide within 14 days whether there was probable cause for the termination. Another, introduced by Sens. Lindsey Graham (R-S.C.) and Cory Booker (D-N.J.), would codify a judicial review before a firing can take place.

Graham, who has cultivated a close friendship with Trump despite characterizing him as a “kook” and “unfit” to be president during the 2016 campaign, previously suggested to The Daily Beast that his own bill was not necessary “ until you show me a reason that Mr. Mueller is in jeopardy.” On Monday, Graham reiterated that he takes the president at his word that he will not fire Mueller.

“We need another special counsel to look at Fusion GPS. But we’re working on a compromise,” Graham told The Daily Beast, referring to Trump’s lawyer’s call for a special counsel investigation into a Justice Department official’s ties to Fusion GPS, the firm responsible for the dossier containing allegations about Trump’s connections to Russia.

Because the bills are slightly different, staffers for each lawmaker and the Senate Judiciary Committee have been working to reconcile the two pieces of legislation into one. As of last week, a committee spokesman told The Daily Beast, aides were still working on the effort. But they’re not in any particular rush to hash out a solution.

“The only thing I saw was the president saying he didn’t have any intentions at all, so we’re still having the discussion but it’s not driven by any current events,” Tillis, the other GOP co-sponsor, told The Daily Beast.

Trump’s allies outside the White House have long questioned the credibility of Mueller’s probe, characterizing it as a “witch hunt.” But in recent days, those same allies—notably, hosts and commentators on Fox News, which Trump watches regularly—have ramped up their attacks against the investigation, which they believe is rampant with anti-Trump biases.

Trump has shown throughout his presidency to be heavily influenced by Fox News, which he tunes into regularly. The network has parroted a barrage of attacks against the Mueller investigation, spurred as of late by the revelation that Peter Strzok, an FBI agent working on the Mueller probe, sent anti-Trump text messages in 2016. Mueller removed Strzok from the investigation after the messages were discovered. ( The Wall Street Journal recently revealed that Strzok also bashed prominent liberals including Sen. Bernie Sanders (I-VT), former Attorney General Eric Holder, and Chelsea Clinton.)

But the accusations of bias on the Mueller team’s part from Fox News personalities began long before Strzok’s messages were publicized. Fox News legal analyst Gregg Jarrett has accused Mueller of weaponizing the FBI, comparing the agency to Russia’s KGB. On Saturday, host Jesse Watters said Trump might be the victim of a “coup” because “the investigation was weaponized to destroy his presidency for partisan political purposes and to disenfranchise millions of American voters.” Top White House adviser Kellyanne Conway told Watters that Mueller’s investigators “can’t possibly be seen as objective or transparent or evenhanded or fair.” Another pro-Trump host on the network, Jeanine Pirro, argued on Saturday that the special counsel probe aims to invalidate the 2016 election results.

While Senate Republicans have largely dismissed those suggestions, some pro-Trump House members have gone as far as to call for a second special counsel to investigate the integrity of the Mueller investigation. One of those lawmakers, Rep. Matt Gaetz (R-FL), who has called for Mueller’s firing, traveled with Trump to a rally in Pensacola, Florida, on Air Force One earlier this month.

For his part, Trump has said as recently as Sunday that he is not considering firing Mueller. He hasn’t gone as far as Watters and Pirro, but he has tweeted that the FBI is “tainted” and in “tatters.” On Capitol Hill, Democrats have raised concerns about the president’s whims. Over the weekend, Rep. Jackie Speier (D-CA) suggested that a Mueller firing is imminent.

Trump cannot technically fire Mueller. But he can direct Deputy Attorney General Rod Rosenstein—who oversees the special counsel investigation—to do so. As recently as last week at a House Judiciary Committee hearing, Rosenstein has stood by Mueller, whom he appointed, and has maintained that there is no “good cause” to fire him or disband the investigation.

For now, Congress is taking Rosenstein and Trump at their word, save for the few lawmakers still pushing for a legislative backstop.

“I think there is urgency to getting to consensus on re-introducing a revised bill. We’ve got language. Getting all four members to actually agree is our current challenge,” Coons, one of the Democratic co-sponsors, told The Daily Beast. “I think it is in the country’s best interest, I think it is in the president’s best interest, I think it is in the best interest of the rule of law, President Trump should not fire Robert Mueller. That would be disastrous.”