Senate Republicans are scrambling to shield special counsel Robert S. Mueller III from mounting GOP fury about new evidence that members of his team were biased against President Trump, as factions of the party charge that his entire investigation is tainted.

The stakes are high: If the GOP moves to hold Mueller accountable for his former subordinates' actions, it could enable Trump to order his ouster and cripple the inquiry he has run examining Russian interference in the 2016 presidential election and whether the president's campaign coordinated with the Kremlin to tilt its outcome in his favor.

But as House Republicans demand that the special counsel face a reckoning over the newly released details of anti-Trump, pro-Hillary Clinton text messages sent between FBI officials Peter Strzok and Lisa Page, Senate Republicans are fighting to preserve Mueller's ability to steer the Russia investigation to its conclusion.

"There's all kinds of reasons to believe there's political interference, and we ought to get to the bottom of it," Senate Judiciary Committee Chairman Charles E. Grassley (R-Iowa) said, adding: "I've got confidence in Mueller, as far as what he's doing in the Trump-Russia investigation, and I don't have any reason to believe otherwise."

Grassley, who is running one of three congressional inquiries looking at aspects of Russian interference in the 2016 campaign, does not usually pull punches in partisan battles surrounding Mueller's investigation. He was one of the first lawmakers this year to call for a second special counsel to look into the circumstances of a 2010 deal that gave Russia a significant stake in the U.S. uranium market, and he now thinks the special counsel could look at the Strzok-Page texts, too.

He was also one of the first and most consistent voices insisting that investigators focus on a dossier of salacious allegations surrounding a trip to Moscow that Trump took in 2013, based on research that the Democratic National Committee and the Clinton campaign later were found to have paid for.

But when asked whether Mueller's former team members' texts were fueling opposition to Mueller's Russia investigation, Grassley's answer was direct: "No."

[Top FBI official assigned to Mueller’s Russia probe said to have been removed after sending anti-Trump texts]

Several other GOP senators echoed that sentiment, taking pains to spare Mueller from censure even as they expressed anger that FBI officials capable of expressing such bias had been allowed on the team.

"Mueller's public service has been commendable up until now. . . . He's a very capable guy, and I don't think you benefit by starting this process over again," said Sen. Roy Blunt (Mo.), a member of the Senate Republican leadership team and the Intelligence Committee, which also is investigating Trump's alleged Russia ties.

"I am concerned that he couldn't put a team together that wasn't so overwhelmingly on one side of the ideological spectrum," he added. "But maybe even somebody as capable and experienced as Mueller can learn a lesson from this."

Others found solace in the fact that Mueller removed Strzok upon learning of his texts with Page, who had left Mueller's team weeks earlier for unrelated reasons. But these lawmakers insisted that the texts were reason to have a second special counsel look into evidence of political bias at the FBI.

"This FBI agent doesn't taint Muller's investigation, because Mueller's going to be responsible for the final product. Mueller fired the guy, I liked that," said Sen. Lindsey O. Graham (R-S.C.), a leading member in the Judiciary Committee's investigation. "But we need to have somebody looking at this other stuff, and it can't be Mueller."

Graham has not shied away from criticizing Trump. But even the president's staunchest supporters in the Senate have made a concerted effort to preserve a decent opinion of Mueller as their estimation of the inquiry has plummeted.

"Set Mueller aside. I don't know. But I have to tell you this: I think those texts, I believe those texts totally taint the investigation that's going on right now," said Sen. James E. Risch (R-Idaho), a senior member of the Intelligence Committee.

"I don't know who hired those people, but they need to be replaced," he continued. When pressed about whether Mueller bore responsibility for assembling his team, he repeatedly declined to draw the connection, insisting, "I'm not going to use those words."

[Rod Rosenstein defends Robert Mueller as GOP lawmakers raise questions of bias in Russia probe]

This sentiment, though problematic for Mueller, still stands in sharp contrast to that in the House, where the special counsel's critics are openly calling for his removal.

Rep. Matt Gaetz (R-Fla.), who last month filed a resolution calling for Mueller to recuse himself from the Russia investigation, said Wednesday that he had been "a lone voice in the wilderness" for the past few weeks. But since the Strzok-Page texts emerged, "now I find a chorus singing loudly behind me," he said.

More voices in the House also are calling for a second special counsel to investigate allegations of pro-Clinton bias at the FBI, as opposed to in the Senate, where the GOP is torn about the value of appointing yet another outside lawyer to look into matters Congress should be able to investigate or the Justice Department should be able to sort out.

"The FBI should look at that issue. . . . I'm not convinced that we need yet another lawyer involved in this," said Sen. John Neely Kennedy (R-La.), a member of the Judiciary Committee, noting that there are "some good lawyers at Justice, and we have some good agents at the FBI, most of them."

"There's a better way to do it rather than have the special counsel for the special counsel for the special counsel," said Sen. James Lankford (R-Okla.), a member of the Intelligence Committee.

But for all of Senate Republicans' efforts to separate Mueller from the politically charged firestorm around him, they have been slow to rally around a legislative venture to protect his control of the Russia investigation.

Along with Graham, Sens. Thom Tillis (R-N.C.), Christopher A. Coons (D-Del.) and Cory Booker (D-N.J.) have been locked in negotiations for weeks trying to finalize a bill that would require a three-judge panel to review, within 10 days, any decision to fire a special counsel.

Grassley has not weighed in on the effort, but has repeatedly said he is concerned about the "constitutionality" of a bill that would subject the president's executive actions to a judicial order.

Read more at PowerPost