'It's mostly a personality test': Iowa poll dissects the GOP race

Former President Trump might skip Wednesday night's debate, but he's ever-present in the minds of voters, according to numbers from the new partnership between NBC News, the Des Moines Register and MediaCom. J. Ann Selzer, the chief pollster behind this latest survey, joins Chuck to detail the toplines — and how most likely GOP Iowa caucusgoers are unlikely to support any candidate who "aggressively criticizes" Trump.