Republican presidential candidate Donald Trump reacts as Republican presidential candidate Sen. Ted Cruz (Texas) rebukes a comment made by Trump during a presidential debate at the University of Miami on March 10, 2016. (Pedro Portal/AP)

Donald Trump branded his rivals as “little,” “low energy,” “lyin’ ” Republicans as he systematically bulldozed them from the primaries.

Now, with the real estate mogul set to formally accept the Republican presidential nomination Thursday night, many of those losing candidates are still trying to figure out their place in a party they barely recognize — cognizant that their political futures may hinge on the success or failure of their approaches to Trump.

In some cases, their plans are consistent with the kind of campaigns they ran. Sen. Ted Cruz of Texas thrived on being loathed by party leaders and appears content continuing as chief villain. Sen. Marco Rubio of Florida, who ran a cautious campaign, has sought a careful balance between warmly embracing Trump and coldly shunning him. Centrists John Kasich and Jeb Bush, two vocal Trump critics, are refusing to fall in line behind the mogul.

There are also some surprises. Wisconsin Gov. Scott Walker, who helped Cruz win his home state primary when he endorsed the Texan against Trump, spoke supportively of the mogul during a speech here this week. Texas Gov. Rick Perry, an early Trump critic, has also come around and spoke at the convention.

Trump is paying close attention. In a speech to donors at a private lunch Thursday, he praised Rubio and Perry but slammed Bush, Kasich and Cruz, according to a Republican who attended the gathering.

Ted Cruz was being loudly cheered by many of the delegates at the Republican National Convention on July 20 – until he urged voters to "vote their conscience." Photo by Michael Robinson-Chavez/The Washington Post (Peter Stevenson,Sarah Parnass,Jorge Ribas,Alice Li,Dalton Bennett/The Washington Post)

The most dramatic posture toward Trump’s candidacy has been adopted by Cruz, who is running for reelection in 2018 and who many Republicans believe is eying a second run for president in 2020. Cruz refused to endorse Trump during a high-profile speech at the convention Wednesday night, a move many Trump supporters saw as a brazen show of disrespect. He drew loud boos in the arena where he spoke.

“He took a gamble,” said Mica Mosbacher, a veteran fundraiser who hauled in cash for Cruz before joining Trump’s team after the senator dropped out of the race. “He was talking to his base and a lot of them weren’t there at the convention.”

Mosbacher added: “It’s sort of brilliant on Trump’s part because he gave Ted Cruz enough rope to hang himself.”

Other holdouts didn’t bother showing up. Kasich, the Ohio governor, skipped the convention, despite it being held in his home state. Bush, a former Florida governor who Trump insultingly dubbed “low energy” during the campaign, also stayed away.

Bryan Williams, chairman of the Summit County Republican Party in Ohio, said that although he disagrees with Kasich’s decision not to back Trump, he’s happy that he didn’t try to do the same thing Cruz did.

“I do respect the fact that he was invited to speak, and he chose not to speak — rather than speak, promote himself and not support the nominee,” said Williams, who initially supported Kasich’s campaign and now backs Trump.

At the Thursday donor lunch, Trump insulted Bush and Kasich for keeping their distance.

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“If I got beaten as bad as Kasich got beaten by me I wouldn’t support him either,” Trump said, according to the Republican who attended the lunch and was granted anonymity to discuss a private meeting. Trump’s spokesman did not respond to a request for comment.

The clashes between Rubio and Trump were some of the most vitriolic of the entire campaign. Trump tried to denigrate Rubio by repeatedly calling him “little Marco.” After months of steering clear of Trump, Rubio abruptly shifted course after a televised debate in Houston, labeling him a “con artist” and lobbed an anatomical insult at him.

Rubio is running for reelection, a reversal of long-stated plans to leave the Senate in 2017 — either as president or a private citizen. When he launched his campaign last month, Rubio explained that he wanted to serve as a check against the next president, because he has worries about both Trump and Democratic candidate Hillary Clinton.

Rubio, who some Republicans believe might run for president again, skipped the convention to focus on his reelection campaign in Florida. But he recorded a video message that was played here Wednesday night in which he said, “The time for fighting each other is over.”

“Unlike Barack Obama and Hillary Clinton, Donald Trump takes seriously the threats from Islamic radicals and is committed to rebuilding our military,” Rubio also said in the video.

Walker, whose presidential campaign fizzled quickly after he launched it to heavy fanfare, might also have a second act on the national stage, some Republicans say. In his speech at the convention Wednesday night, he contrasted Trump with Clinton.

“Donald Trump is standing with the American people,” he said. “We want a leader who is not afraid to take on the mess in Washington.”

Earlier this month, Walker attracted attention with a tweet voicing strained support for Trump. He didn’t mention Trump’s name.

“Last August, I said I’d support the GOP nominee. It’s now clear who the RNC delegates will vote to nominate. And he is better than she is,” he tweeted.

Perry, who after two straight defeats in presidential primaries seems like he has run his last campaign for the White House, once labeled Trump’s candidacy a “cancer on conservatism.”

He sung a different tune in his convention speech Monday night, nodding to Trump’s signature theme as he introduced former Navy SEAL Marcus Luttrell.

“Making America great again starts by taking care of our veterans,” Perry said.