By JOE WILLIAMS, LINDSEY McPHERSON and REMA RAHMAN

Even as House and Senate Republicans turned up the heat on the Trump White House for answers about the firing of FBI Director James B. Comey, Democrats got a big win when the Justice Department appointed former FBI Director Robert Mueller as special counsel to investigate alleged Russian meddling in the 2016 election, including any connections to the Trump presidential campaign.

Key committees in both chambers on Wednesday pressed the administration for documentation on communication between President Donald Trump and Comey, who has been asked to testify before Congress. Those efforts, though, could be affected by Mueller’s appointment, as key players in ongoing federal investigations are typically loath to testify in public settings. 

Deputy Attorney General Rod Rosenstein made the appointment the day before he was set to brief senators on Comey’s termination.

Senate Minority Leader Charles E. Schumer, who one day earlier warned his colleagues on the floor that “history is watching,” applauded the move. 

“A special counsel is very much needed in this situation and Deputy Attorney General Rosenstein has done the right thing. Former Director Mueller is exactly the right kind of individual for this job. I now have significantly greater confidence that the investigation will follow the facts wherever they lead,” the New York Democrat said in a statement. 

“My initial reaction is Mueller is somebody who I think will do an honest job,” House Minority Whip Steny Hoyer told reporters. “And he needs to do a vigorous job because the allegations have extraordinarily serious ramifications for our county”

House Intelligence ranking member Adam B. Schiff, whose panel is conducting its own Russia investigation, also praised the move to install Mueller, Comey’s predecessor at the FBI. 

“I think this was the right decision and the right candidate for that job,” the California Democrat said. 

Senate Majority Leader Mitch McConnell, who has resisted calls for outside investigations, released a matter-of-fact statement about the development.

“The decision by the Deputy Attorney General to appoint former FBI Director Robert Mueller as a special counsel confirms that the investigation into Russian intervention into our election will continue, as stated last week by Acting FBI Director Andrew McCabe. The Senate Select Committee on Intelligence will also continue its investigation into this matter,” the Kentucky Republican said. 

House Speaker Paul D. Ryan followed shortly after with his own statement, saying the special counsel appointment is consistent with his goal “to ensure thorough and independent investigations are allowed to follow the facts wherever they may lead.”

“That is what we’ve been doing here in the House,” the Wisconsin Republican added, noting that those bipartisan investigations will continue.

While GOP leaders were relatively slow to respond officially to the news, their rank and file was downright chirpy about it. 

“I think it’s a good move on behalf of the administration to do this, and it means that they’re taking things seriously,” said North Carolina Rep. Mark Meadows, the chairman of the House Freedom Caucus. 

“People are going to have their passions fired up out here, but I hope this restores some trust in the American people that we’ll get to the right answers,” Illinois Rep. Adam Kinzinger said.

Kinzinger said he doesn’t know Mueller well. “Just watching him from the sidelines, I guess, I thought he was very respectful, very bipartisan, getting some stuff done,” he said.

One of Trump’s most steadfast allies, New York Republican Rep. Chris Collins, said Mueller’s appointment came as a relief. He said the pressure was now off congressional Republicans to comment on the need for a special counsel.

“The one positive development would be that we don’t have to answer that question anymore,” Collins said. 

Lawmakers spent much of Wednesday addressing questions about a report published Tuesday evening which, citing memos from Comey, alleged that Trump tried to influence a federal investigation into one of his top allies, ousted national security adviser Michael Flynn, and Flynn’s connections to Russian officials.

Before the Mueller news broke, the presence of any controversy in the halls of Congress would have been difficult to tell by listening to GOP leaders. Ryan and McConnell both spent the morning making a pitch for overhauling the tax code. 

“The opportunities like this come around only once in a generation,” Ryan told reporters during his weekly press briefing.

“Rather than bury our economy in an avalanche of red tape, like the last administration, it’s time for a new direction on regulations — smarter and pro-growth,” McConnell said during his opening remarks on the Senate floor. “Passing tax reform legislation would mark a major achievement in bringing us closer to that goal. This Republican Congress and administration have made it a priority from the start.”

Ryan largely side-stepped commenting on the allegations facing the White House, except to say he continues to have confidence in Trump. Ryan and McConnell both expressed support for congressional committees requesting documentation and inviting Comey to testify.

But the chaos of the week, which also included reports that Trump shared classified information with Russian officials in the Oval Office last week, weighed on rank-and-file members. 

Rep. Carlos Curbelo, for instance, said Tuesday night that the allegations against Trump, if true, could fit the definition of obstruction of justice, which the Florida Republican noted has historically been an “impeachable offense.”

Rep. Justin Amash, said early Wednesday that if reports that Trump tried to interfere in the ongoing FBI investigation were accurate, it could be grounds for impeachment. 

“If the allegations are true, yes,” the Michigan Republican said.

Amash, a member of the conservative Freedom Caucus, has been calling for an independent commission to look into ties between Trump’s associates and Russia, a notion supported by all 193 Democrats in the House.

But despite the increasing use of the word impeachment in the House, senators on both sides of the aisle largely brushed off the topic.

“Others can do what they want, but I’m not going to get involved in that speculation,” Senate Minority Whip Richard J. Durbin. “We have an orderly process in our government. We’re going to follow it.”

That didn’t mean Republicans spared the White House of criticism, though.

“I think what’s needed is more discipline and credibility from the administration,” Alaska Sen. Dan Sullivan said. “It’s the key to getting everything done. We have a big agenda to attack … and we need discipline and credibility from the executive branch.”

House Democrats on Wednesday tried to take action into their own hands by using a procedural vote to push for legislation calling for an independent commission. While their motion failed, they have also launched a discharge petition to force a vote on legislation to establish the commission. At least one Republican — Rep. Walter B. Jones of North Carolina — has signed on.

Kinzinger, while praising Mueller’s selection as special counsel, said Congress should hold off on an independent commission, at least at this point.

“Let’s let this thing take,” he said. “Some people are going to be disappointed because it takes away a political talking point. But the reality is now let’s let this thing go forward and see [what] happens. If we want to start popping up all kinds of different investigations everywhere, this is never going to get solved.”

Jones said this week’s allegations “raise some real legitimate questions of impropriety,” but stopped short of saying Trump’s actions could merit impeachment.

Meanwhile, starting next week, Congress may get their chance to get answers to several questions about the multiple controversies. 

Sens. Richard M. Burr, R-N.C., and Mark Warner, R-Va., leaders of the chamber’s Intelligence Committee, announced Wednesday that they invited Comey to speak to the panel in both an open and closed session. This comes less than a week after he declined a separate invitation from the committee.

The invitation comes with the support of McConnell.

“It’s appropriate and timely for the Senate to hear directly from former Director James Comey in a public setting as part of the Senate Intelligence Committee’s ongoing investigation,” the Kentucky Republican told Roll Call in a statement.

House Oversight and Government Reform Chairman Jason Chaffetz also said he would invite Comey to testify in front of his committee next Wednesday. A Ryan spokeswoman said he supported Chaffetz’s decision.  

Rep. Elijah E. Cummings, the Oversight panel’s top Democrat, said he expected that if Comey were to testify, he would do it by his own rules and would make just one appearance before lawmakers on Capitol Hill, despite multiple invitations to testify.

“A lot of people don’t do that,” the Maryland Democrat said. “And he’s going to dictate his terms. If it were me, I’d say one appearance, period. One and done.”

The House Intelligence Committee is also investigating the alleged Russian meddling. 

“I don’t believe it will have an impact on us at all,” said Rep. K. Michael Conaway, who is leading the panel’s Russia probe.

The Texas Republican declined to say whether his committee was adding the recent allegations raised in the news to his inquiry.

“I don’t talk about the details,” he said.

The Mueller appointment also came as The Washington Post reported that House Majority Leader Kevin McCarthy, in a leaked recording from 2016, told fellow Republicans that Trump, along with Rep. Dana Rohrabacher, R-Calif., may have received payments from Russian President Vladimir Putin. 

McCarthy said Wednesday his comments were a “bad attempt at a joke.” 

“You don’t have a sense of humor anymore? You’re not supposed to be able to laugh?” the California Republican told reporters when asked why he would joke about that subject.

McCarthy said, “If you listen to it … you know it’s a bad attempt at a joke, and that’s all there is to it. No one believes it to be true.”

The timing could not have been much worse, regardless of intent. 

Niels Lesniewski, Bridget Bowman and Simone Pathé contributed to this story. 

Correction 10:32 p.m. | An earlier version of this story incorrectly described Florida Republican Rep. Carlos Curbelo’s comments about impeachment with respect to the allegations against President Donald Trump.