MILWAUKEE — She once called Donald Trump unstable and unfit to serve a second term in the Oval Office. He once questioned the former president’s age and stamina, mocking him for losing to Joe Biden in 2020.

But on Tuesday, the second day of the Republican National Convention, former South Carolina Gov. Nikki Haley and Florida Gov. Ron DeSantis bent the knee in front of Trump, who sat in a red VIP box and ate up the scene alongside family members, dozens of elected officials and thousands of cheering RNC delegates.

It’s a redemption arc so common in the modern GOP that Trump’s own running mate, Ohio Sen. JD Vance, followed it: He went from a staunch critic who once called Trump “noxious” and “America’s Hitler” to a loyal ally on his ticket.

The message the GOP sought to portray was clear: Unlike the Democratic Party, in its state of disarray, we are united in our effort to win the presidency and take total control of Congress in November.

Haley was met by some boos when she stepped onstage. But she quickly won over the crowd by endorsing Trump for another term, saying the country would be worse off under four more years of Biden.

“We have to acknowledge there are people who don’t agree with Donald Trump 100 percent of the time. I happen to know some of them, and I want to speak to them tonight,” Haley said. “My message to them is simple: You don’t have to agree with Trump 100 percent of the time to vote for him. Take it from me: I haven’t always agreed with President Trump. But we agree more often than we disagree.”

“We have a country to save and a unified Republican Party is essential to saving her,” she added, bringing the delegates to their feet and eliciting chants of “USA.”

The former South Carolina governor, who was the first prominent woman of color to seek the GOP presidential nomination, also included a plea to expand the party. “We are so much better when we are bigger,” she said.

DeSantis’ speech, by comparison, was far more aggressive and focused on attacking Democrats and “woke” policies, a favorite theme of his GOP primary campaign.

“Let’s be honest here. Biden is just a figurehead. He’s a tool for imposing a leftist agenda on the American people,” DeSantis said, before teeing up an attack on Biden’s age.

“America cannot afford four more years of a ‘Weekend at Bernie’s’ presidency,” he said.

The Florida governor who spoke Tuesday night couldn’t have been more different from the defiant version of DeSantis GOP voters saw on the primary campaign trail. DeSantis said of Trump in January: “You can be the most worthless Republican in America, but if you kiss the ring, he’ll say you’re wonderful.”

Most attendees at the convention downplayed Haley’s past criticism of Trump and welcomed her back into the fold.

“People say a lot of things in politics. And I think Donald Trump has enough thick skin by now,” Rick Lawrence, an RNC delegate from Aurora, Illinois, told HuffPost.

But Debbie Epling, chair of the Aiken County GOP in South Carolina, said she didn’t think Haley had really changed her thinking on Trump — just her political calculations.

“I think it’s politics,” she said. “I have never seen an election where one person got up on a debate stage and said, ‘I can’t stand this person, I can’t stand that person,’ and after the primary, they’re best friends.”

Some of Trump’s former 2016 presidential rivals, now strong backers of the nominee, also delivered prime-time remarks at the convention Tuesday.

Sen. Ted Cruz (R-Texas), who ended his convention speech in 2016 by telling delegates to “vote your conscience” following a bitter rivalry with Trump, issued a glowing endorsement of the former president in an immigrant-bashing speech, embracing his slogan to “Make America Great Again.”

And Sen. Marco Rubio (R-Fla.), a foreign policy hawk who once called Trump a “con artist” that couldn’t be trusted with the presidential nuclear codes, also heaped praise on the former president and his MAGA agenda. In his speech, the senator warned that another Biden term in office would make the world less safe.

“There is nothing dangerous or divisive about putting Americans first. Putting Americans first must be what this election is about,” Rubio insisted, garnering applause from Trump.