Corn on Hardball: Whose Super-PACs Are Airing the Nastiest Ads in Iowa?

David Corn and former Republican National Committee chairman Michael Steele appeared on MSNBC’s Hardball to discuss the barrage of mudslinging GOP campaign ads that have been airing on televisions across Iowa. With less than two weeks until the Iowa caucuses, which negative ads are influencing voters, and who’s paying for them to air?