HOUSTON -- Marco Rubio and Ted Cruz unleashed a searing barrage of attacks on Donald Trump Thursday night, seeking to use the final debate before Super Tuesday to derail the New York billionaire’s seemingly inevitable march to the Republican nomination.

The heated face off underscored the stakes: Georgia, Texas and 10 other states are set to vote Tuesday, when nearly a quarter of the total GOP delegates in the nation will be awarded. Trump is riding the momentum of three commanding back-to-back wins. He steamrolls into Super Tuesday atop the polls in a number of states, including Georgia.

Battling to consolidate GOP establishment support, Rubio debuted a sharp new tone with the front runner Thursday. He lambasted Trump for everything from his failed university venture to his company’s bankruptcies, to his inconsistent views on health care and even mocking his wealth as something he simply inherited from his father. Rubio also homed in on Trump’s signature issue, saying the real estate mogul had been talking tough on illegal immigration — including building a wall along the Mexican border — after hiring undocumented workers.

“If he builds the wall the way he built Trump Towers he’s gonna be using illegal immigrants to do it,” the Florida senator said.

Trump fired back by touting his record creating jobs.

“I’m the only one on the stage that’s hired people…I hired tens of thousands of people,” Trump replied.

“Many of them from other countries,” Rubio shot back.

“Just be quiet and let me talk,” Trump mumbled.

Cruz joined in the assault on Trump, questioning his conservative credentials by asking whether he would use religious liberty as a litmus test in selecting a U.S. Supreme Court nominee to replace Antonin Scalia, the conservative justice who died earlier this month.

Trump mocked Cruz for his filibusters in the U.S. Senate that went nowhere, scoffing that Cruz can’t make deals needed to get things done.

“You get along with nobody,” Trump said. “But you don’t have one Republican senator backing you; not one. You don’t have the endorsement of one Republican senator and you work with these people. You should be ashamed of yourself.”

“I will not apologize for a minute for defending the Constitution,” Cruz said. “I will not apologize for defending the Bill of Rights.”

Cruz added that while he was in the trenches working on conservative causes like immigration, “you were firing Dennis Rodman on ‘Celebrity Apprentice.’”

CNN’s debate moderator, Wolf Blitzer, at times lost control of the proceeding as Cruz, Rubio and Trump pressed their attacks, sometimes talking over one another and over Blitzer, too.

Rubio got off some wicked one-liners at Trump’s expense — “I guess there’s a statute of limitations on lies,” and “the Palestinians are not a real estate deal, Donald.”

And Trump was typically pugnacious, even with the debate’s questioners. He ridiculed questioner Hugh Hewitt’s radio show and told Telemundo anchor Maria Celeste Arraras that “I don’t believe anything Telemundo says.” At one point he gestured first toward Rubio and then toward Cruz and said, “This guy’s a choke artist, and this guy’s a liar.”

The debate came in Cruz’s hometown of Houston. Delegate-rich Texas is widely believed to be must win state for Cruz. Still, polls here show the race tightening with Trump gaining ground.

Cruz is seeking to prove that his win in Iowa was no fluke. Since then, he has notched a pair of disappointing third-place finishes South Carolina and Nevada. In South Carolina, he trailed Trump among evangelical voters who are supposed to be the Texas senator’s base.

For Rubio — who has landed in the runner-up slot in the last two states — the debate offered a chance to prove he can take on Trump, who has excelled at churlishly swatting away would-be rivals.

Former Ohio Gov. John Kasich and neurosurgeon Ben Carson are both trailing the lead pack, languishing in the single digits in most polls. They were relegated to supporting roles Thursday night.

At one point Kasich clarified his position on same-sex marriage saying that he believes the Supreme Court has settled the issue and that those who oppose it should still “sell them a cupcake.”

“I mean, if you’re in the business of commerce, conduct commerce. That’s my view. And if you don’t agree with their lifestyle, say a prayer for them when they leave and hope they change their behavior,” he said.

Carson drew some chuckles when he was asked how he would decide on a potential Supreme Court nominee, he replied that “the fruit salad of their life is what I will look at.”

And he bemoaned his role as a bystander to the action. “Can someone attack me please?” Carson asked at one point after being left out of a feisty back-and-forth over foreign policy

Trump was on the defensive most of the night, but also suggested that he would be the best candidate to take on Hillary Clinton, who is leading the race for the Democratic nomination.

Curiously, he also made several comments that seemed destined to inflame critics on the right.

At one point he said that since he would defund Planned Parenthood because it performs abortions but then went on to defend the group which is anathema among many conservatives.

“Millions and millions of women — cervical cancer, breast cancer — are helped by Planned Parenthood,” he said.

“So you can say whatever you want, but they have millions of women going through Planned Parenthood that are helped greatly. And I wouldn’t fund it.”

Trump has also faced repeated questions about whether he has a strong enough commitment to repealing Obamacare. Yet Thursday night he sounded a compassionate note, saying the government must ensure that no one will be left to “die sitting in the middle of the street.”

Asked whether his views of healthcare coverage are close to those of Sen. Bernie Sanders, who advocates a single payer system, Trump declared: “I’m closer to common sense.”