Then-President-elect Donald Trump is seen at Mar-a-Lago in Florida in December with Chief of Staff Reince Priebus, right, and Michael Flynn, who resigned as national security adviser on Monday. (Jim Watson/AFP/Getty Images)

Congressional Republicans are finding it increasingly difficult to defend President Trump after a tempestuous start to his term that has stoked frustration, fatigue and fear on Capitol Hill.

Some are at a loss for words when asked about Trump’s un­or­tho­dox national security decisions. Others strain to sidestep current stumbles in hopes that conservative legislative achievements will eventually render them irrelevant. And a growing number warn that uncertainty about West Wing staffing and such controversies as Trump’s unilateral immigration ban have detracted from their top priorities.

“There are distractions,” said Rep. Charlie Dent (R-Pa.). “They need to become more disciplined and more focused on their messages, and they have to get more active on policy development.”

Both chambers and the White House will have an opportunity to address their differences during Tuesday’s weekly Senate GOP policy lunch. Vice President Pence and Speaker Paul D. Ryan (R-Wis.) will attend and speak, according to their offices.

Many congressional Republicans have endured Trump’s unpredictability — including his criticism of the federal judiciary and an immigration order that caught them by surprise and drew intense national blowback and a legal rebuke — because they believe he holds the key to passing the laws they have talked about for years.

“Conservatives do and should view him as their current best chance to get conservative policy enacted into law because that was the grand bargain made,” said Rory Cooper, a Republican strategist who opposed Trump’s candidacy for president. “The idea was they would overlook certain behaviors and distractions from President Trump in anticipation of being able to have a willing signature on the other end of conservative legislation.”

Rep. Mark Meadows (R-N.C.), chairman of the Freedom Caucus, a conservative group of House members, put it this way: “I would rather accomplish something with distractions than not accomplish anything with smooth sailing.”

But on some of the major issues Republicans have vowed to tackle, including repealing and replacing the Affordable Care Act and imposing tax cuts through comprehensive tax reform, there remains a glaring lack of consensus, leaving uncertainty about when and how things will get done.

In the meantime, a growing list of controversies has made it harder for some Republicans to shrug off the president’s behavior. The latest disturbance: the resignation of Michael Flynn as national security adviser over possibly illegal communication with Russia. Other surprise developments have also unnerved Republicans, including Trump’s decision to effectively turn his Mar-a-Lago Club terrace into an open-air situation room.

“You can’t make it up,” Senate Armed Services Committee Chairman John McCain (R-Ariz.) said with a laugh when asked about the Mar-a-Lago story as he stepped into an elevator Monday.

Sen. Pat Roberts (R-Kan.), a former chairman of the Senate Intelligence Committee, said: “I don’t know if it’s improper. How about untoward. That’s a good word, right?”

(Bastien Inzaurralde/The Washington Post)

And Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.) said he hadn’t heard about the weekend incident in which Trump and Japanese Prime Minister Shinzo Abe discussed a North Korean missile test with other club members nearby.

“Yeah. Huh,” Corker said when brought up to speed by a reporter. “Thanks.” Then he walked away.

The White House and some GOP congressional leaders have sought to downplay signs of discord. White House press secretary Sean Spicer argued last week that the president is “actively seeking” input from Congress “and helping them craft an agenda to move the country forward.”

Pence, a familiar face on Capitol Hill from his days in the House, has been a frequent visitor in recent weeks. He met with some GOP House members Monday.

But it’s clear his presence alone will not soothe concerns. Some of Trump’s top allies say they have had to deal with blowback from fellow Republicans reminiscent of the skepticism that surfaced during the campaign.

“It’s been concerns. I don’t want to overdo it,” said Rep. Chris Collins (R-N.Y.). “But of course there has been some.” He did not specify who was complaining.

Meanwhile, amid speculation about further White House staffing changes beyond Flynn, Republican lawmakers expressed growing anxiety about the fate of the president’s chief of staff, Reince Priebus. Priebus is seen by many on Capitol Hill as a stabilizing force in a turbulent operation.

“A bunch of us feel the need to come to the guy’s defense. But does that help him or not? We just don’t know — we just don’t know,” said one Republican senator who spoke on the condition of anonymity to frankly convey the feelings of several of his colleagues. “But yeah, we worry about that.”

Some in the president’s orbit have been critical of Priebus. Trump has defended Priebus, telling reporters Monday that he has done a “great” job.

High atop Republicans’ wish list right now is confirming Trump’s nominee for the Supreme Court, Judge Neil Gorsuch. His pick of Gorsuch to fill the seat of the late justice Antonin Scalia was widely praised by Republicans on Capitol Hill. Many said it helped undo some of the damage caused by Trump’s immigration ban.

However, the confirmation process has already grown complicated. Trump has bluntly called on Senate Republican leaders to deploy the “nuclear option” of dramatically changing Senate rules to confirm Gorsuch with a simple majority if they can’t put enough cracks in the wall of Democratic resistance. Senate Majority Leader Mitch McConnell (R-Ky.), a devotee of Senate tradition and custom, is hoping that he never has to face that decision.

Gorsuch faces a critical day on Tuesday: Five of the six senators he plans to meet with are Democrats.

Trump’s early unpopularity among the public has raised questions about whether his support in Congress will further erode. According to the most recent Gallup daily tracking poll, his job approval rating stands at just 40 percent, with 54 percent disapproving.

For some Republicans, the preferred way of defending Trump is to pivot away from him altogether.

“I think they are taking it very seriously,” said Sen. Ron Johnson (R-Wis.), chairman of the Senate Homeland Security and Governmental Affairs Committee, when asked about Trump’s public deliberations about North Korea at Mar-a-Lago. “Look at the mess the previous administration left for this administration to deal with.”

Johnson then launched into an extended attack on different parts of Barack Obama’s foreign policy record as president.

Sen. Bill Cassidy (R-La.), who has proposed a plan to replace key parts of the Affordable Care Act, said he is focused on that, as well getting up to speed on tax reform, another GOP priority.

“If I react to every leak and headline and spin,” he said, “I end up incredibly distracted not doing my task at hand.”

Kelsey Snell and Aaron Blake contributed to this report.