What a Trump-free debate will mean for the GOP candidates

Aired: 1/28/2016 | 0:03:35 | Clip
There's a Republican debate in Iowa Thursday night, but the front-runner who has most frequently dominated the spotlight will not be there. Political director Lisa Desjardins talks with Judy Woodruff about Donald Trump’s debate dropout, what the GOP candidates will try to achieve on stage, plus a new ad by Democratic candidate Sen. Bernie Sanders.