Donald Trump's rivals have all said they will back him if he is the Republican presidential nominee in November - the friendliest moment in an otherwise testy debate.
It seemed the candidates had finally hit rock bottom last week, when Donald Trump and Marco Rubio swung back and forth at each other over spray tans, heavy sweating, and pants-wetting.
Asked to respond to the criticism, Trump dismissed Romney as a "failed candidate" who was "an embarrassment to everybody" when he lost to President Obama in 2012.
Pawlenty said there's still time to defeat Trump.
Earlier in the day, McCain released a statement echoing worries voiced by 2012 GOP nominee Mitt Romney during his Thursday press conference in Utah.
Watch Mitt Romney's full speech at the Hinckley Institute of Politics in Salt Lake City, Utah on Thursday.
To say that numerous previous debates have been unintelligible might be an understatement, so for those of you who are looking for some substance, the candidates might actually have time to speak tonight.
Rubio's initial attack about Trump's hands happened at a Sunday rally in Virginia. Marco Rubio (R-FL) in Florida.
The debate also marked the apparently friendly reunion of Fox News anchor Megyn Kelly and Donald Trump. Rubio asked, grinning. Holding his hands up, Trump declared, "I guarantee you, there's no problem" in that area. But the big turnout you are seeing is both pro-Trump and anti-Trump, so there are record numbers of people coming because of Donald Trump, but not just to be for him.
Ohio Gov. John Kasich said, "I kind of think before it's all said and done I'll be the nominee". He also claimed that Trump regularly flip-flops on his positions.
Trump said it was simply business.
Rubio in recent days revived a decades-old old insult, mocking Trump for having relatively slight hands. And Florida and OH have tons of them - tons of delegates Kasich and Rubio will want to keep out of Trump's pockets.