Republicans in Washington are coming to grips with the increasing likelihood that Donald Trump Donald John TrumpHR McMaster says president's policy to withdraw troops from Afghanistan is 'unwise' Cast of 'Parks and Rec' reunite for virtual town hall to address Wisconsin voters Biden says Trump should step down over coronavirus response MORE will be their presidential nominee.

It’s a scenario few would have taken seriously last summer, when Trump jumped into the race against what Republicans believed was their strongest presidential field in decades.

ADVERTISEMENT

But the real estate mogul has nearly vanquished them all, winning three out of the first four contests by double-digit margins while leaving his closest remaining rivals — Sens. Marco Rubio Marco Antonio RubioFlorida senators pushing to keep Daylight Savings Time during pandemic Hillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll Intelligence chief says Congress will get some in-person election security briefings MORE (Fla.) and Ted Cruz Rafael (Ted) Edward CruzLoeffler calls for hearing in wake of Netflix's 'Cuties' Health care in the crosshairs with new Trump Supreme Court list 'Parks and Rec' cast members hosting special reunion to raise money for Wisconsin Democrats MORE (Texas) — in the dust.

With surveys putting him ahead in most of the states set to vote in next week’s Super Tuesday contests, Trump is on the verge of acquiring a delegate lead that could prove insurmountable.

Following his resounding victory in the Nevada caucuses Tuesday, at least two Republican lawmakers said it’s time for their party to stop fighting the Trump phenomenon.

Reps. Chris Collins (N.Y.) and Duncan Hunter (Calif.) on Wednesday became the first members of Congress to endorse Trump. Collins, who hails from the billionaire’s home state of New York and had previously endorsed Jeb Bush’s White House bid, cited Trump’s business background.

“If we want to get our nation’s economy growing again and deal with the daunting fiscal issues threatening America’s future, it’s time to say no to professional politicians and yes to someone who has created jobs and grown a business,” Collins said in the statement.

“We’re electing a chief executive, not a chief politician,” Collins told The Buffalo News.

Hunter, who first endorsed Mike Huckabee, praised Trump’s “guts” and “fortitude” and predicted to Politico that other lawmakers might soon start to “come out of the closet” in support of him.

While Trump hasn’t received a single endorsement from Senate Republicans, Sen. Jeff Sessions Jefferson (Jeff) Beauregard SessionsTrump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status White House officials voted by show of hands on 2018 family separations: report MORE (R-Ala.) — who has been supportive of Trump and Cruz— expressed confidence that his colleagues would come around if Trump triumphs in the end.

“I think he’s going to need to show discipline and more specificity ... and I’ll think he’ll do fine. He certainly has brain power,” Sessions told The Hill.

“I’ll tell you what I tell my colleagues: I don’t know what side you’re on, but I’m on the people’s side. I don’t think Washington is doing very well, either.”

While many Republican lawmakers have been critical of Trump, particularly for his call to temporarily ban most Muslims from entering the United States, there appears to be a growing realization that his march to the nomination might be unstoppable.

“I think there’s increasing fear from some of them that he’ll be the nominee. And there’s going to be less resistance to him as a result,” said Rep. Justin Amash Justin AmashOn The Trail: How Nancy Pelosi could improbably become president History is on Edward Snowden's side: Now it's time to give him a full pardon Trump says he's considering Snowden pardon MORE (R-Mich.), who has endorsed Cruz.

Senate Republicans, wary of alienating Trump’s conservative supporters, are increasingly falling in line behind the strategy of offering support for whoever wins the nomination.

But not everyone is ready to give Trump a full embrace.

Congressional endorsements are still flowing to Rubio despite his failure to win a single caucus or primary.

Sen. Jeff Flake Jeffrey (Jeff) Lane FlakeRepublican former Michigan governor says he's voting for Biden Maybe they just don't like cowboys: The president is successful, some just don't like his style Bush endorsing Biden? Don't hold your breath MORE (R-Ariz.), who endorsed Rubio this week, suggested that while some Republicans were “surprised” and “very concerned” about Trump’s win in Nevada, he believes it’s more likely that Trump won’t be the party’s nominee.

“It’s more difficult after last night; let’s face it, that was a bigger win than we thought,” he said. “But I don’t think it’s too late, people get more serious, very few delegates have been awarded yet.”

Meanwhile, Sen. Lindsey Graham Lindsey Olin GrahamThe Hill's Campaign Report: Arizona shifts towards Biden | Biden prepares for drive-in town hall | New Biden ad targets Latino voters Senate Democrats' campaign arm announces seven-figure investment to boost Graham challenger Graham: Comey to testify about FBI's Russia probe, Mueller declined invitation MORE (R-S.C.), one of Trump’s most vocal critics, warned Wednesday that the GOP will be “slaughtered” if the businessman is the nominee. He refused to say whether he would vote for him, despite having signed a “loyalty pledge” to back the nominee during his own failed White House run.

“Well, I’ll cross that bridge when I get there,” Graham told reporters, adding that Republicans have less than a week to stop Trump’s momentum.

If Trump wins two-thirds of the delegates in the

March 1 Super Tuesday contests, as polls suggest he might, Graham said the GOP race would effectively be over.

“You’re not really going to be able to take it away from him at the convention,” Graham said.

After Nevada’s caucuses, Trump has 81 delegates, compared to 17 for Cruz, 17 for Rubio, six for John Kasich and four for Ben Carson. Eleven states and American Samoa will award delegates on Super Tuesday, amounting to about a quarter of all the outstanding delegates.

A handful of Republicans maintain that they will refuse to vote for Trump no matter what.

Rep. Carlos Curbelo (R-Fla.), a freshman who faces a tough reelection race this year, said Trump is a “fraud” and “offensive.”

“I could never look my children in the eye and tell them that I supported someone like that to be president of the most important and the greatest nation in the world,” Curbelo told The Hill.

The Cuban-American lawmaker, who had endorsed Bush but switched his allegiance to Rubio this week, suggested alternatives to Trump could still emerge.

“Maybe we’ll get some new candidates after the conventions,” Curbelo said. “A lot can happen from here to the end of summer.”

Amash, a libertarian and member of the House Freedom Caucus, also said he would not support Trump if he’s the nominee.

“I’m really concerned that the reaction from a large segment of our party has been to support someone who doesn’t really care much about our Constitution, who seems to believe the ends justify the means. In many respects, it’s similar to the thinking of the establishment. It’s just a different kind of establishment,” Amash said.

GOP leaders have largely avoided making public judgments about Trump while tacitly acknowledging that he has a good chance of being atop the ticket.

Speaker Paul Ryan Paul Davis RyanAt indoor rally, Pence says election runs through Wisconsin Juan Williams: Breaking down the debates Peterson faces fight of his career in deep-red Minnesota district MORE (R-Wis.), who is staying neutral in the GOP primaries, dodged a question about Trump at a Wednesday press conference and has sidestepped queries about the race for weeks. But he has weighed in on occasion: Ryan condemned Trump’s proposal to ban Muslims from the U.S. late last year.

And Rep. Greg Walden (R-Ore.), who runs House Republicans’ campaign arm, tried to downplay a potential Trump effect down the ballot. “Both parties are going to have issues with their nominee, whoever the nominee is,” he said.

Still, House Majority Leader Kevin McCarthy (R-Calif.) said earlier this week that there’s a greater than 50 percent chance that Trump becomes the GOP nominee, adding that he could work with him.

Despite GOP lawmakers’ reservations about Trump, Amash suggested Republicans have no one to blame but themselves for his rise.

“It’s the fault of Republicans in Congress. It’s the fault of the GOP leadership. They don’t seem to recognize the anger and distrust that people feel toward Congress,” Amash said.

Graham, however, offered up another culprit: The tactics of Cruz, who is competing with Trump for the nomination.

“Ted Cruz and others have made people believe we could repeal ObamaCare if we wanted to and we just didn’t want to, which is a complete lie,” Graham said. “There’s been an effort to create a dynamic where we’re the problem.”

Jonathan Easley contributed.