Republican presidential candidates held their  final debate  last night in Sioux City just weeks before the Iowa caucus takes place on January 3. In the Fox News debate candidates attempted to draw distinctions from one another and defend their record to conservative voters. The latest  New York Times/CBS News poll  shows Newt Gingrich gaining ground on consistent front runner Mitt Romney. But some  voters  are still undecided. Todd Zwillich is The Takeaway's Washington correspondent and Louise Story is Wall Street and finance reporter for  The New York Times. They examine the facts behind last night's debate.