Washington (CNN) As storm clouds continue to gather over President Donald Trump, congressional Republicans are doing the political equivalent of sheltering in place -- bracing themselves and hoping to ride out the controversy.

Spurred by reports that Trump asked then-FBI Director James Comey to drop the investigation into former national security adviser Michael Flynn, Democrats are demanding an independent investigation into Trump's actions, calling for a special prosecutor, and in some cases raising the possibility of impeachment.

But Republicans are hamstrung by a simple reality: Their political fortunes are still directly tied to Trump's.

GOP lawmakers still have to answer to a base that remains overwhelmingly behind the President. Launching new investigations and a special prosecutor could drag the issue out well past the 2018 midterm elections. And they see Trump as a useful ally in their pushes for tax reform, health care changes and more -- if they can ever get back to working on policy.

It's all part of why House Speaker Paul Ryan tried to buy the GOP time and offered Trump some cover Wednesday, telling reporters the current congressional investigations are sufficient and that he wants to wait and see the memos Comey drafted after his meetings with Trump.

"The last thing I'm going to do is pre-judge anything," Ryan told reporters. "I'm a person who wants to get the facts."

Senate Foreign Relations Committee Chairman Bob Corker also said he wanted to wait and see.

"We all should take a deep breath and hopefully Comey will come before the committees in public very soon," Corker said. "We're at a point now where until Comey comes up and testifies publicly and we actually know more about what's happened, there's really nothing else to say, is there?"

Even one of the most outspoken critics of Trump's moves with Comey, Arizona Sen. John McCain, admitted that it "does grow a little boring" to answer the same questions all day long, but at this point, it's all Republicans can do given that they're still waiting for answers to their own questions.

GOP lawmakers know Comey is likely to testify publicly before a congressional panel in the near future and that there are still more notes based on his conversations with Trump that are likely to be revealed.

Risks to agenda

Some Republicans in vulnerable seats have sharply criticized Trump. "It's a major distraction for the Congress, and it's just bad for the psyche of every American," Florida Republican Rep. Carlos Curbelo told reporters off the House floor Tuesday.

Others are lamenting that their messages on tax reform, health care and more are being drowned out by the controversies surrounding Trump.

House Democrats, meanwhile, attempted a new tactic Wednesday, forcing a vote on whether to launch an independent investigation into Trump and his campaign's ties to Russia. But the GOP majority was able to sidestep it.

As Trump's approval rating has dipped -- it's at 40%, according to a recent Quinnipiac poll -- so have voters' views of the GOP. In that same poll, 54% of Americans said they want to see Democrats control the House, to just 38% for Republicans -- the biggest margin the poll has ever found.

Across Capitol Hill, members and their staff are tired of the drip, drip, drip of new allegations and evidence damaging to Trump coming out every day.

"We're all exhausted because we'd love to actually focus on the things people elected us to do," one Senate GOP aide said.

But, turning on Trump now would almost certainly derail the GOP's agenda of repealing Obamacare and overhauling the country's tax system. On Wednesday morning during a closed-door meeting with his conference, Ryan encouraged his members to be "sober" about how they approached the huge volume of information coming out every day about the President. Facts first, he instructed.

A Republican president, after all -- even one has sloppy at times or as controversial as Trump -- still can provide the signature Republicans need to finally pass some of their central campaign promises. But GOP lawmakers admit that the distractions from the White House have still taken their toll.

"We've been discussing health care in lunches and private meetings, so that work continues," said Sen. Susan Collins, a Republican from Maine and member of the Senate Intelligence Committee. "But obviously there's new revelations coming every day in the press concerning the White House. It makes it more difficult for us to pursue an agenda here."

Democrats, of course, have watched their Republican colleagues closely as they've squirmed with every passing Trump controversy. From the outside, Democrats say their colleagues are facing a hard political choice.

"It's just a question of political instincts. Right now, the Republicans in their primary and the Republicans who voted for Trump are still overwhelmingly in his corner and they're afraid of alienating them," said Democratic Sen. Dick Durbin of Illinois, who added that Republicans are now caught between appeasing their base and the rest of the country.

"It's reaching a level where it's beyond the routine political decision," Durbin said.

Sen. Chris Van Hollen, a Democrat from Maryland, said he is concerned that Republicans who are voicing criticism privately have not done so publicly.

"All I can say is, this is the time to be patriots over partisans," Van Hollen said.