Transcript for GOP Debate: Who Came Out on Top?
The ABC news debate in Iowa where there were some fierce exchanges among the Republicans who would be president and -- -- even defining moment. GMA co anchor George Stephanopoulos was right in the thick -- that moderating the debate alongside Diane Sawyer. And -- joins us now from the site of the showdown there into mowing George good morning to you. Good morning -- You know just 24 days are 23 days to go -- as Iowa Caucuses so we were ready for the candidates to come in and really go added and they did -- there was no. No holding back last night at all he saw -- -- -- take a lot of fire from just about everyone on the station weathered it. A pretty well you saw Michelle Bachmann and Rick Santorum tried to get back users to -- him anyway and they had strong performances. As well is that defining moment for Mitt Romney. The battle is already going crazy on Twitter will CL -- holds up. Over time but all of these attacks but we knew where signaled going and that's why want to bring in John Berman but they were a little bit. Reversed John weren't they all the signals coming in to this debate where that. Newton Newt Gingrich is going to be the statesman pay these attacks and there was going to be Mitt Romney on offense. I George I thought this was genuinely surprising. -- -- the big question was how far would Mitt Romney go would Mitt Romney attacked Newt Gingrich wouldn't Mitt Romney mix it up but the stunning thing that happened was. Newt Gingrich did -- first. There's one. Starts are simply. -- Gingrich promised he would stay above the fray but during this bruising debate he didn't stay above the fray he made the -- On Mitt Romney's claim he's not a career politician the only reason you didn't become a career politician as you lost a Teddy Kennedy in 1994. -- eyewitness. It was a blistering start in if you -- charge Mitt Romney you need a dash. They might have been the debate's most remarkable moment that he thinks he is preparing over health -- or read your first book. And it said in there that your mandate. In Massachusetts. We should be the model for the country and I know it came out. Of of them the reprint of the book but you know I'm -- saying he referred individual -- -- friend out -- 101000 bucks. 101000 dollar -- I'm not in -- business -- okay. Kerry -- -- in this -- Romney's book but that 101000 dollar bet. From a multimillionaire. Twitter nearly exploded thousands of tweak its three months Paper the average American in -- Gingrich and Romney were joined together on stage. Michelle Bachmann join them in -- If you look at -- Romney favor for the illegal immigration problem if you look at new Romney neighbor for this 700 billion dollar bailout you just heard. New Romney is also with Obama on the issue of a key role. Extension issue the Middle East group Gingrich defended his clean that the Palestinians. Argue -- people. It's fundamentally -- for -- they have the guts to stand up and say enough lying about the Middle East -- Romney's response to we're gonna tell the truth. But we're not gonna throw incendiary words in -- way 88 place which is a boiling pot. There was a palpable moment of tension about the issue of marital infidelity. Remember Gingrich has been married three times if you cheat on your spouse. Then why would you cheat on your business partner Newt's response than people have to look at person to whom -- -- -- the presidency. And then after they -- the right to ask every single question. Gingrich said that all of that harp and most others that came his way flashing winks and shrugs and handshakes. And smiles -- more. In 101000 dollars. Now overnight the Romney team was spitting that 101000 dollar debt by saying. It's the kind of thing you say around the dinner table -- -- you're wrong I think to a million bucks you're wrong. The problem is with everyone talking about it so much this morning it is tougher than and I did here for some key Romney supporters overnight George and they're concerned. I'm nice talent -- have a joke coming from it reminded could -- Ellen okay John Berman thanks trumps. Of serious very few people has have as sharp political mind as you do so I really wanna hear. Do you think there was a clear winner last night and did this debate changed the game in a significant way. I think I think it did it it was an important debate for this reason he -- this was the first debate last night. And Newt -- coming -- as -- unparalleled. Front -- and the first debate where Mitt Romney actually had to do something to stop. The momentum. Of Gingrich and although I think -- setting aside that 101000 dollar batting Romney had a decent. Night but but and -- didn't do anything at all and dignity do anything at all that would stop I think. Speaker Gingrich -- momentum going to last night the speaker -- all he attacks he kept that smile. On his face -- been so many questions about his temperament wouldn't blow at some point that didn't happen as well and I thought the speaker actually. Really help himself when he answered that question about his is his personal life and his marriage -- and really made it tale. Redemption I I do think. That it was a good night for the so called second tier candidates -- especially probably Michelle Bachmann who I think found her way back into this race. By tying together. Romney and Gingrich and one of the things you certainly saw in the hall last night is that Ron Paul has a solid base. Of support in Iowa and in these Republican primaries and caucuses and he probably had as many applause line is anyone else. Last night but it's coming into this debate last night. Newt Gingrich was a front runner and on the rise. He may not still be rising but he is still clearly the front runner after last night he handled that is very very well you can't hold much of people now scrambling to see. If there's something else they can do. In these final -- three weeks before the Iowa Caucuses to slow him down put -- stop to that momentum.
This transcript has been automatically generated and may not be 100% accurate.