"I think he could change the electoral map in ways we haven't seen before," Cornyn said when asked if he was worried about the Trump impact down-ticket. "This disrupts the usual Republican vs. Democrat, conservative vs. liberal paradigm, and I think we don't know how this will all play out. I think it will be OK."
"You don't need to despair," the Texas Republican added with a laugh.
Cornyn isn't alone. House and Senate Republicans are reluctantly coming to terms with the reality that the real estate mogul -- a man many feared given his unpredictability, questionable policy positions and lack of discipline on the campaign trail -- will likely be their party's standard bearer. Rather than fight it, a number of Republicans say, it may be time to embrace it.
"Many of us who have expressed concerns are reconciling ourselves to the fact that in all likelihood he will be the eventual nominee," said Rep. Mark Sanford of South Carolina, who backs Sen. Ted Cruz
After Trump delivered a foreign policy speech in Washington on Wednesday, some top Republicans were highly laudatory of the billionaire's positions, including Tennessee Sen. Bob Corker, who called the speech "very thoughtful."
Corker, chairman of the Senate Foreign Relations Committee and a close ally of Senate Majority Mitch McConnell, said with a chuckle that the fact that Trump scares some world leaders could be a good thing for the United States.
"I did say to my staff that is somewhat of a welcome change," Corker said. "There is some good that comes with that."
Utah Sen. Orrin Hatch, the longest-serving Senate Republican, said Thursday he'd do "everything in my power" to help Trump if he's the nominee.
"I think he can be great if he'll get serious about being president -- and I think he will," Hatch said. "He's a clever, smart guy who will want to be remembered for doing great things. I have a feeling he can make that transition."
Behind the scenes, the Trump campaign is trying to broaden support on Capitol Hill. On Thursday, senior Trump adviser Paul Manafort continued the latest in a round of weekly outreach meetings, sitting down with roughly 16 House Republicans just steps from the Capitol. Afterward, Rep. Mike Kelly, who voted for Trump in Pennsylvania's primary on Tuesday, said he has been hearing more favorable reviews of the businessman in recent days.
"I think on the floor, there's a lot stronger support for Donald Trump then people possibly imagine," Kelly said.
While many conservatives aren't ready to publicly endorse Trump, some privately admit that they don't want to criticize him and antagonize his supporters, whom they will need to turn out in November to retain control of Congress.
Rep. Raul Labrador, an Idaho Republican who has endorsed Cruz, told reporters Wednesday that he's sympathetic to the concerns about Washington voiced by Trump backers.
"This is a way to give Congress and the Republican Party the middle finger," Labrador, a member of the conservative House Freedom Caucus, said of voting for Trump.
The comments reflect the hardening reality among Republicans on Capitol Hill that despite how unnerved many are about Trump, they realize they must recognize the will of GOP voters and get behind the businessman -- or risk seeing Hillary Clinton
, the likely Democratic nominee, as the next president. Moreover, many Republicans frankly fear that a messy nominating convention could be far worse than choosing Trump as their nominee.
And also, a number of Senate Republicans simply refuse to support Cruz because they don't think he has much of a chance to win the nomination and are irked at the way he's treated his colleagues.
With Trump as their likely nominee, Rep. Thomas Massie, a libertarian Kentucky Republican, said many Republicans will need "counseling."
"These folks should start enrolling today," Massie said.
If Trump wins, 'we get creamed'
Of course, many Republicans are still wary or downright opposed to Trump. And some patently fear that Trump would be romped by Clinton
, costing the GOP the House and the Senate in the process.
"If he's the nominee, we get creamed," said South Carolina Sen. Lindsey Graham
, a former presidential candidate who now backs Cruz. "We're going to get killed with women and Hispanics. It's going to be a wipeout."
Cruz is banking on next week's Indiana primary to reset the race, hoping a victory in the Hoosier State will help deny Trump the 1,237 delegates he needs to secure the nomination before the July convention.
"If he wins Indiana, it's over," Graham said of Trump.
Rep. Carlos Curbelo, who represents a Miami-area district, is one of the most endangered House Republicans in the country -- and he strongly opposes Trump.
"No," Rep. Justin Amash of Michigan, a Cruz supporter, said when asked if he could back Trump in the general election.
"Some of his ideas are fine," Amash said. "Others are terrible."
Said Rep. John Kline of Minnesota: "Certainly his tone, I find annoying to the very least."
But Kline added: "He's not my choice, but I'm going to support the nominee.
Better than 2008?
Right after Trump delivered his first major policy speech on foreign policy, House Speaker Paul Ryan
was across town trying to court millennial voters at Georgetown University. Ryan continues to avoid weighing in on Trump, but when one young college Republican asked for advice on how to pick between two GOP candidates he didn't support -- Trump and Cruz -- Ryan said, "Look at the policies, not the person."
But Ryan has called on his colleagues to attend the GOP convention
and unite behind the nominee, no matter who it is.
Similarly, Rep. Jim Jordan of Ohio, who chairs the House Freedom Caucus group of conservatives, has been publicly neutral in the race
. He told reporters the GOP race was "not over" with more states yet to vote, but also said that he would back Trump if he was the party's nominee.
Jordan argued that his party's handling of immigration policy fueled the support for an outsider candidate like Trump, saying, "We disappoint them and they said 'enough, 'We've had it' and it's the one issue that I think started the whole Trump phenomenon."
Alabama Rep. Gary Palmer, who was elected in 2014, warned establishment Republicans not to dismiss the concerns of Trump supporters angry at Washington.
"We should be sitting down talking to these people who have been carved out of the system. You know our party talks about a big tent -- these people built the tent, and we forgot and they are the people coming out to vote for Donald Trump," Palmer said.
Yet no matter how much concern there is about Trump, some top Republicans say it could be a lot worse.
"It's hard for me to believe," said Oklahoma Rep. Tom Cole, "that it will be a lot worse than 2008 when we had two unpopular wars, a financial crisis 40 days before an election on our watch, an incumbent Republican president with 30% approval, two points higher than Richard Nixon the day he resigned."