HOUSTON -- The GOP presidential candidates barreled into the final stretch to Super Tuesday after a name-calling, insult-trading, finger-pointing final debate in which Marco Rubio and Ted Cruz engaged in a tag-team attack intended to take down front-runner Donald Trump before it's too late.
"I've dealt with tougher," Trump sniffed after taking incoming for two-plus hours Thursday night. He said he knew the attacks were coming because "they're desperate. They're losing by massive amounts."
Rubio kept up the pressure Friday morning, using an appearance on national television to declare that "Donald Trump is a con artist. He is wholly unprepared to be president of the United States."
Eleven states vote in Tuesday's mega-round of voting, with 595 delegates at stake. Trump, with three straight victories behind him, has the momentum, and his rivals know they have to change that dynamic to have any hope of derailing his streamroll toward the nomination.
It was far from clear, though, that the two senators did much to solve their basic conundrum -- each struggling to emerge as the clear alternative to the front-runner as non-Trump voters continue to splinter their support among the alternatives.
From Houston, the GOP candidates spread out in the hunt for Super Tuesday votes, with Cruz headed for Tennessee and Virginia on Friday. Both Trump and Rubio are signaling they're unwilling to cede Texas, the crown jewel of Super Tuesday, to the home state senator, Cruz. Each scheduled campaign events in Texas before heading to Oklahoma City.
Up until Thursday, Rubio and Cruz had shown little willingness to take on Trump when the national spotlight shines the brightest. That all changed in Houston.
Rubio was the principal aggressor, spitting out a steady stream of criticism on everything from Trump's position on immigration to his privileged background, his speaking style and more. Cruz was happy to pile on, too, questioning the front-runner's conservative credentials, foreign policy savvy and electability.
In one testy moment, Rubio speculated that if Trump "hadn't inherited $200 million, you know where Donald Trump would be right now? Selling watches in Manhattan."
Not long after that, he took on Trump's declaration that he'd build a wall on the Mexican border, declaring: "If he builds a wall the way he built Trump Tower he'll be using illegal immigrant labor to do it."
He also accused Trump of shifting his position on deportation, hiring people from other countries to take jobs from Americans and being fined for worker violations.
Joining in, Cruz criticized Trump for suggesting he alone had "discovered the issue of illegal immigration."
Both said Trump had had to pay a $1 million fine for illegal immigration hiring.
It was a rare night where the bombastic Trump, standing between the two senators, found himself on the defensive.
He was hardly silent, responding to both Rubio and Cruz: "This guy's a choke artist and this guy's a liar. ... Other than that I rest my case."
Afterward, Trump called it "really one of my best debates -- considering that I was being hit from all sides."
All three candidates were pressed on why they haven't released their tax returns as promised. The GOP's 2012 nominee, Mitt Romney, suggested this week that Trump was holding back because there was a "bombshell" in there. Trump said he's been audited by the IRS every year and can't release his returns while that's going on.
Cruz and Rubio, for their parts, promised to release their 2014 returns in the next day or two.
Trump, known for his frequent use of coarse and profane language on the campaign trail, scolded former Mexican President Vicente Fox for using a profanity in talking about Trump's plan for the wall.
"He should be ashamed of himself and he should apologize," declared Trump.
After Trump mocked Rubio for his "meltdown" in a previous debate when the Florida senator repeated rote talking points, Rubio swatted back in kind, scolding Trump for spouting the same phrases over and over: "Everyone's dumb. He's going to make America great again. We're going to win, win, win. He's winning in the polls."
While Rubio was loaded for bear from the start, Cruz ramped up his criticism as the night wore on and argued that Trump wouldn't be an effective opponent against Hillary Clinton in the general election.
As for Trump's plans to negotiate a solution to the Mideast conflict, Cruz said: "He thinks Palestinians are a real estate deal."
Making light of Cruz's repeated attempts to diminish him, Trump said: "Keep fighting, keep swinging, man, swing for the fences."
There was this back-and-forth after one particularly heated exchange:
Cruz to Trump: "Donald, relax."
Trump to Cruz: "I'm relaxed. You're the basket case."
The other two remaining candidates, Ben Carson and John Kasich, were largely left to watch the fireworks flying overhead.
At one point, as the top three candidates mixed it up, Carson appealed: "Can somebody attack me, please?"
-- Nancy Benac reported from Washington. Associated Press writer Laurie Kellman in Washington contributed to this report.