Amid a period of major upheaval in the GOP primary race comes tonight’s Republican presidential debate in Tampa – the 17th showdown to date, and the first since former House speaker Newt Gingrich’s (R-Ga.) come-from-behind win in South Carolina on Saturday.

View Photo Gallery: Amid a period of major upheaval in the GOP primary race, Republican presidential candidates debated again – the 17th showdown to date, and the first since former House speaker Newt Gingrich’s (R-Ga.) come-from-behind win in South Carolina on Saturday.

Caution was the name of the game at Monday night’s Republican presidential debate in Tampa – the candidates’ 17th showdown to date, and the first since former House speaker Newt Gingrich’s (R-Ga.) come-from-behind win in South Carolina on Saturday.

Mitt Romney, vying with Gingrich for front-runner status ahead of Florida’s Jan. 31 primary, quickly moved to criticize Gingrich’s tenure as House speaker and his work for mortgage lender Freddie Mac, with Gingrich shooting back that Romney’s claim that he had worked as a lobbyist was a “false charge.”

But less than halfway through the debate, the showdown took a turn for the subdued, and the candidates-- influenced in part by an unusually restrained audience -- largely echoed each other in their answers to questions on local hot topics such as illegal immigration and NASA funding. Our play-by-play of the night is below.

» Romney hits Gingrich on Freddie Mac
» Mitt Romney taps former Bachmann strategist for debate prep
» Florida Republican debate: What to watch for
» Florida, Florida, Florida: A Sunshine State political primer


10:52 p.m. | Romney: I made Ted Kennedy take out a mortgage in ’94 race

The debate winds down with a question from Brian Williams to the candidates on their conservative bona fides.

Mitt Romney responds with a reference to his record as Massachusetts governor as well as his 1994 Senate bid against then-Sen. Ted Kennedy (D-Mass.).

“What a great thrill that was,” Romney says. “I didn’t beat him, but he had to take a mortgage out on his house to defeat me.”

It’s a line that Romney has said in previous debates, but one that – given the now-heightened scrutiny on his finances – could come back to haunt him.

Rep. Ron Paul (R-Texas), who has uttered some of the few lines that have received applause from the audience tonight, answers the question by arguing that the rest of the field is out-of-step when it comes to the definition of a true conservative.

“How can you be conservative and cut food stamps but you won’t cut spending overseas? ... We have to decide what ‘conservative’ means and what limited government means,” he says, contending that it’s up to candidates to adhere to the Constitution.

10:38 p.m. | Bush-era tax cuts prevented ‘deeper slump,’ Gingrich says

Newt Gingrich is asked to defend the Bush-era tax cuts. His response: The cuts, which are set to expire at the end of this year, “stopped us from going into a much deeper slump.”

The debate then takes a detour away from national issues and into more local ones, including the future of NASA, subsidies for the sugar industry and even a hypothetical question about the 2005 Terry Schiavo case.

“It should certainly be a priority,” Romney says of NASA funding, making a nod to Florida’s Space Coast.

Gingrich says that NASA funding and the promotion of private-sector innovation “are not incompatible.” He says he’d like to see “vastly more of the money” spent on encouraging the private sector, but at the same time also would like to see a “leaner NASA.”

10:35 p.m. | Calm in the crowd

Unlike the last raucous Republican debates, this one is notable for the lack of audience participation. Moderator Brian Williams asked the crowd not to applaud in his introductory remarrks. The Twitterverse has taken note. :

I kind of miss the loud, boisterous audience. #fldebate

— The Fix (@TheFix) January 24, 2012

@TheFix The quiet is going to bring out the real debate talent. No red meat for the sake of red meat.

— Matt Hooper (@hoopermatt) January 24, 2012

I like the fact that there’s not a fawning crowd to cheer at the applause lines.Make the debaters sharper #fldebate

— Tim Farley (@MorningBriefing) January 24, 2012

NBC debate without applause is like Jay Leno with no applause and laughs.

— Andrew Kaczynski (@AKaczynski1) January 24, 2012

10:30 p.m. | Fred Thompson endorses Gingrich

Former senator, actor and 2008 presidential candidate Fred Thompson endorsed Newt Gingrich on Sean Hannity’s Fox News program.

TPM reports Thompson told Hannity:

“I have come to the growing realization that Newt Gingrich is the guy who can articulate what America is all about ... make the case and not just read the talking points” when it comes to topics like American exceptionalism, free markets “and our basic case that lower taxes can be good for everybody.”

10:23 p.m. | Romney argues for ‘self-deportation’

Mitt Romney introduces what sounds like a novel solution to the problem of illegal immigration: self-deportation, rather than the federal government “rounding up” those who have come to the country illegally.

Meanwhile, he and Newt Gingrich strike a similar note on the issue of the DREAM Act. Gingrich says he would not sign the measure as it currently stands.

The legislation provides a path to citizenship for certain young people who were brought to the United States illegally as young children, have lived in the country for at least five years, have a U.S. high school diploma and have completed two years of college or military service.

“I would work to get a signable version, which I think would be the military component,” Gingrich says.

Notes Romney: “That’s the same position that I have, and that is, I would not sign the DREAM Act as it currently exists, but I would sign the DREAM Act if it were focused on military service.”

National Journal’s Beth Reinhard asks the field: Why is it acceptable for candidates to court voters in Spanish but unacceptable for the government to serve them in Spanish?

Gingrich – who has made Hispanic outreach a centerpiece of his campaign -- responds first. “I think campaigning, historically, you’ve always been willing to go to people on their terms and their culture. But as a country, to unify ourselves in the future ... I think it is essential to have a central language that we expect people to learn.”

He adds that he would work to make election ballots available only in English.

Romney says that “Speaker Gingrich is right with regard to what he described.”

10:06 p.m. | Let’s agree to agree

The stakes tonight are higher than they have been in most any other GOP showdown, coming after a different candidate won each of the first three states.

And yet, an hour into the debate, the candidates seem to be less intent on drawing sharp contrasts with one another than they have in the past.

Mitt Romney and Newt Gingrich have agreed on one issue: Both think that that the Dodd-Frank financial regulatory reform bill was a bad idea.

“When you put that much authority in the Treasury Department under Geithner, it’s an invitation to corruption,” Gingrich says.

Romney argues that the financial industry “was poorly regulated” before its collapse in 2008.

“You need to have regulation that’s up-to-date,” he says. “They had old regulation that was burdensome.” He adds that he believes Dodd-Frank has made things even worse.

The conversation then moves on to Cuba – a major issue among Florida GOP primary voters. Yet the greatest contrast between Gingrich and Romney appears to be not on policy, but rather on the issue of whether Fidel Castro is going to heaven or hell.

“I don’t think that Fidel’s going to meet his maker,” Gingrich quips. “I think he’s going to a different place.”

Rather than Gingrich or Romney, it’s Rep. Ron Paul (R-Texas) who distinguishes himself from the field, arguing against the U.S. embargo against Cuba.

“I think we’re living in the dark ages when we can’t even talk to the Cuban people. ... I think it’s not 1962 anymore,” he says.

The GOP hopefuls also field a round of questions on Iran. Paul again positions himself against his rivals.

“We don’t have any money,” he says. “We have too many wars. ... The most foolish thing in the world right now would be to take on Iran.”

9:46 p.m. | ‘You just jumped a long way over here, friend’

Where did Brian Williams go?

For more than five minutes, Mitt Romney and Newt Gingrich engage in a heated one-on-one battle over their records, with Romney charging that Gingrich worked as a lobbyist for Freddie Mac.

Gingrich calls the accusation that he was a lobbyist a “false charge” and says that his contract with the mortgage giant states “very clearly, I was supposed to do consulting work.”

“There’s a point in this process when it gets unnecessarily personal and nasty, and that’s sad. ... I think it’s pretty clear to say that I have never, ever gone and done any lobbying,” Gingrich says.

Romney fires back.

“You said you were paid $300,000 by Freddie Mac as an historian,” he says. “They don’t pay people $25,000 a month for six years as an historian. ... This contract proves that you were not an historian, you were a consultant.”

Gingrich defends his work and shoots Romney a question of his own.

“What’s the gross revenue of Bain during the years you were working for them?”

Romney responds that he didn’t do any government-related work during his years at Bain Capital and Bain & Co. By contrast, he argues, “we have congressmen who say that you came and lobbied them with regard to Medicare Part D.”

Says a defiant Gingrich: “You just jumped a long way over here, friend. ... I publicly favored Medicare Part D for a practical reason.”

It’s tough to see either candidate decisively coming out on top of the exchange: Gingrich has come prepared to defend himself, while Romney has come prepped to attack, and neither has effectively scored a point against the other – or, for that matter, won the applause of the audience.

Meanwhile, Romney again comes under scrutiny for his tax returns, which his campaign announced on Sunday it will release tomorrow.

“Oh, I’m sure people will talk about it,” Romney says in response to a question from Brian Williams. He adds: “You’ll see how complicated taxes can be. But I pay all the taxes that are legally required, and not a dollar more. ... Is it entirely legal and fair? Absolutely. I’m proud of the fact that I pay a lot of taxes.”

Would Romney follow the precedent his father set and release 12 years of income taxes? Williams asks.

Romney demurs.

“You know, I agree with my dad on a lot of things, but we also disagree,” he says. “And going out with 12 years of returns is not something that I’m going to do.”

9:30 p.m. | A subdued crowd, and a subdued debate -- thus far

We’re not in South Carolina anymore.

In contrast to last week’s debates in the Palmetto State, tonight’s Tampa crowd is far more subdued. And it seems to be rubbing off on the candidates – rather than last Thursday’s combative showdown in North Charleston, tonight’s debate has been civil so far.

Moderator Brian Williams asks Rick Santorum to make his case on the issue of electability, noting that the former Pennsylvania senator sustained a massive 18-point loss to Sen. Bob Casey (D-Pa.) in 2006. Santorum appears well prepared for the question.

“It was a meltdown year,” he says. “We lost 23 out of 33 senators.”

Williams then turns to Rep. Ron Paul (R-Texas) and asks him for an “honest answer” on whether or not he plans to run as a third-party candidate.

“I have no plans to do that; no intention,” Paul responds.

Would Paul support Newt Gingrich as his party’s nominee? Williams asks.

“If I could just change him on foreign policy, we might be able to talk business,” Paul says with a laugh.

9:15 p.m. | Gingrich defends his tenure as speaker

Everything old is new again.

We’re 10 minutes into the debate, and it’s a heated two-man fight between Mitt Romney and Newt Gingrich over Gingrich’s tenure as House speaker.

“At the end of four years, he had to resign in disgrace,” Romney says of Gingrich, adding that since serving in the House, the former speaker has been “working as an influence peddler in Washington.”

Romney – who has tended to train his fire on President Obama in previous debates – is now endeavoring to draw a sharp contrast with Gingrich in the wake of Saturday’s South Carolina primary.

“When I was fighting against cap-and-trade, the speaker was sitting down on a sofa with Nancy Pelosi encouraging it,” Romney says. He also makes note of Gingrich’s criticism of House Budget Chairman Paul Ryan’s (R-Wis.) 2012 budget blueprint as “right-wing social engineering.”

Gingrich’s response?

“He just said at least four things that were false,” Gingrich says of Romney. He adds: “This is the worst kind of trivial politics.”

He also contends that he’s the only speaker since the 1920s who led House Republicans to three consecutive victories.

9:07 p.m. | Santorum: ‘It’s not my responsibility’ to correct claims that Obama is Muslim’

Former senator Rick Santorum (R-Pa.) responds to criticism of his handling at a campaign event of a question from an attendee who asserted that President Obama is Muslim:

“Why do you guys ask these ‘gotcha’ questions, like it’s my job to go out and correct everybody who says something I don’t agree with? ... I don’t think it’s my responsibility. Why don’t you go out and correct her? It’s not my responsibility as a candidate to go out and correct everybody who makes a statement that I disagree with.”

9:01 p.m. | ‘Newt Gingrich. Mr. Washington Insider’

The debate hasn’t even started, but already the Romney camp is gearing up to hit Newt Gingrich hard for his tenure as House speaker.

In a Web video, “Mr. Washington Insider,” Romney’s campaign takes aim at Gingrich’s years in Washington, including the House’s vote to reprimand the former speaker for violating the chamber’s ethics rules.

Click above to watch the 90-second video is above, which is likely a preview of things to come in tonight’s showdown in Tampa.

8:37 p.m. | Gingrich releases his Freddie Mac contract

As promised, Newt Gingrich released his contract with Freddie Mac tonight.

The release comes as Mitt Romney has stepped up his calls for the former House speaker to reveal his contract with the mortgage lender, which paid Gingrich a total of $1.6 million.

Gingrich’s contract can be found here.