Transcript for GOP Contenders Set to Duke It Out
Your voice your vote we're heading into perhaps the most high stakes events in the Republican race for president we just weeks ago until the Iowa Caucuses tonight. Is the ABC news debate there are two clear front runners now Mitt Romney. And Newt Gingrich Diane Sawyer who is moderating the debate -- George Stephanopoulos has called this a political high noon. So let's go straight out ABC John Berman who's in the morning at the Drake university at -- site of tonight's debate John good morning to you. Good morning again what a moment for this debate the atmosphere and Iowa he's simply electric. Mostly because Mitt Romney has taken -- campaign to a whole new level a fairly negative one and the question is when he walks on this speech tonight. How far will -- go in will Newt Gingrich -- spot. Gets up to that podium really Heath wrote down. He tells BBC news I'd expect that Newt Gingrich and I -- have some differences and will be able a discuss those as well but -- he discussed and or will he did skills he like his campaign which is once the poor crumpled immediate assault. On video he doesn't have the discipline that you wanted to present supporters on radio. Your mind isn't so hot. And -- discipline and commitment are terrible. And he says and it's not meet. Heaven knows I can't write a script for all the people -- support me put Romney himself refused to say that Gingrich's two divorces should not be a factor for voters. Back at -- which thinks they. They're allowed to consider which things -- not. Gingrich backers say he will not work. I want -- our. -- people we we understand a lot of crap when he had. And that isn't what -- -- caucuses or elections here in Iowa. In -- new takes the stage we -- he fight then. He did -- Romney's failure to back the contract with America in 1994. He couldn't possibly have been -- -- contract -- -- you how do you let him messages -- reluctant Teddy Kennedy favoring big Gingrich contract. In of course what about the others trying to break through Ron Paul Michelle Bachmann Rick Santorum. You can't buy out. And Rick Perry who will try to rebuild his image that keeps taking hits -- when he said there were eight Supreme Court justices instead of nine. In court remember -- me. -- -- Not not a month month month and or. -- and settlement sit Sotomayor. Right now take a look at this did you wanna point something out -- Mitt Romney in new Gingrich will be standing about two feet apart side by side. So if Mitt Romney goes after Newt Gingrich if you -- Gingrich goes after Mitt Romney. We could get pretty young comparable. Beyond -- -- there right next to each other all right John thank you. -- stage is set for the biggest Republican debate yet and ABC's Jake Tapper continues our special coverage this morning from the site of tonight's crucial showdown Jake good morning to you know. Good morning -- Jacque we're likely to see something tonight that we haven't seen throughout all of these debates and that's Newt Gingrich on the defensive much has been made of -- temperament in the past we've seen out IC can be with reporters that bid. And address and in question his record and what can they expect to see if in fact his opponents do the same thing tonight. -- He Newt Gingrich is arguably had. The best debate performances. Of any of the candidates but this will be the first one where he is being attacked that they cannot -- his opponents cannot let him. Get away with having another great divorce debate performance without them trying to knock him off his game. And the challenges you point out is for him not to show. Any signs that he has a temperament issue he needs to defend himself while also not appearing defensive he needs to. Explain his positions that are being challenged everywhere you turn here in Iowa without what -- also see me. Presidential I -- I Gingrich advisor what are we gonna see from him the advisor said I'm not exactly sure we're still working out the strategy but you can expect Newt Gingrich to be in the role. Of Rocky Balboa no of course as a Philly boy I don't think Rocky Balboa did not win that first. In -- observation -- -- want to turn to Mitt Romney a lot of pressure on him to move ahead in the polls. What is that going to require tonight isn't the words of John Berman and him having to -- down. I love you quoting John Berman to me. But -- I think that he needs to. Seem presidential. Seem commanding -- also explaining. Why these differences that he -- with Newt Gingrich are legitimate for him to point now. Why it's not negative campaigning if he points out that he Gingrich. Have different views on some issues you know Romney four years ago. Are earned a reputation among Republican voters here in Iowa and also among his fellow Republican candidates of being a negative campaign -- -- that really hurt him long term. He has held his fire so far until this week. Because he's been able to because he's been the front runner now he is fighting it all cylinders firing -- all cylinders and he needs to be. Pointing out these differences while also not being mr. negative while also is still being charming and that is going to be a challenge for him as well. The attention will be focused on those two men we appreciate your time -- we know you'll be covering more of this tonight thank you. Thanks yeah. And be sure to join Diane Sawyer and George Stephanopoulos will be moderating tonight's Republican debate in Des Moines, Iowa which -- across the ABC network -- 9 eastern 6 Pacific and before the debate download -- into now app on your iPad or iPhone. It's a brand new way for you to weigh in with your opinions on the debate as it's happening at this -- and -- --
This transcript has been automatically generated and may not be 100% accurate.