Republican debate in Detroit sees Ted Cruz, Marco Rubio blitz Donald Trump

U.S. Republican presidential front-runner Donald Trump came under withering fire from rivals Marco Rubio and Ted Cruz at a debate on Thursday as establishment Republicans tried to muster some unity behind a last-ditch anti-Trump effort.

The Fox News Channel debate became a mud-throwing fracas with tensions mounting over the New York billionaire's ascendancy and his drive to be the presumptive nominee should he win nominating contests in Florida and Ohio on March 15.

At center stage, Trump, 69, defended himself from criticism earlier in the day from 2012 Republican nominee Mitt Romney and faced further questions about his business record.

U.S. senators Rubio, of Florida, and Cruz, of Texas, questioned Trump's immigration policy and his use of foreign workers at his exclusive Mar-a-Lago resort in Palm Beach, Florida.

Cruz, 45, demanded Trump release the audiotape of an off-the-record session he had with New York Times editorial writers on Jan. 5.

Cruz and others have suggested that in the session Trump might have been more flexible on immigration than in his public statements insisting he will build a wall between the United States and Mexico and deport 11 million illegal immigrants.

Trump refused to release the tape but said he would be flexible, for instance, on the height of the wall. He also abruptly changed his position on foreign workers, saying more of them who are highly skilled should be allowed to remain in the United States.

"Release the tape," Cruz told Trump.

"You're the liar," said Trump.

FOREIGN WORKERS

Rubio pressed Trump on the foreign workers he has imported to work at his Palm Beach resort, jobs he said could go to Americans. Trump said the workers are for a short November-to-March season.

"People don't want a short-term job," Trump said. "So we bring people in and we send people out."

Rubio, 44, asked Trump why he does not bring his clothing-making operations to the United States from China and Mexico if he is so interested in bring jobs home, a central tenet of his unconventional campaign.

"This little guy has lied so much about my record," Trump responded, adding that he had begun bringing some clothing operations home from overseas.

But Rubio persisted: "The answer is he's not going to do it ... The reason he makes it in China and Mexico is because he can make more money on it."

"Don't worry about it, little Marco, I will," Trump said dismissively.

"Well, let's hear it, big Donald," Rubio responded.

The debate went down a negative path when Trump responded to Rubio's contention last month that Trump had "small hands."

"Look at these hands," Trump said, flashing his two hands to the crowd. To the suggestion that he might be small elsewhere, Trump said: "I guarantee you there is no problem."

SUPPORT FOR CLINTON

Cruz suggested Trump would be the wrong candidate to send into battle against Democratic front-runner Hillary Clinton because he has supported her financially in the past.

"Actually it was for business," Trump replied. "Let me tell you something, Ted, the last person that Hillary Clinton wants to face is Donald Trump."

Trump was joined on stage at the Fox Theater by his three remaining rivals, Rubio, Cruz and Ohio Governor John Kasich, 63.

It's a far smaller field than the 17 Republican candidates that began the race for the 2016 presidential nomination, but one that is still splintered between the incendiary New York businessman and three experienced politicians.

The debate was the candidates' first face-to-face gathering since Super Tuesday nominating contests this week gave extra momentum to Trump but did not knock out his rivals.

Mainstream figures in the party are seeking a strategy to halt Trump's march to the nomination for the Nov. 8 election to succeed Democratic President Barack Obama.

Some party leaders and donors are critical of Trump's positions on trade and immigration, including his calls to build a wall between the United States and Mexico, deport 11 million illegal immigrants and temporarily bar Muslims from entering the country.

At the debate, Trump was questioned for the first time since last year by Fox News anchor Megyn Kelly, who angered him with her questioning at the Republicans' first debate on Aug. 6, prompting him to cancel participation in a debate in Iowa in January, a move that appeared to cost him some votes.

Trump was on his best behavior with her.

"Nice to be with you, Megyn. You're looking well," he said.