Gingrich to Romney: 'You know some of the ads aren't true'

Newt Gingrich criticized Mitt Romney during the Facebook/NBC debate on Sunday morning over ads run by a super-PAC supporting the former Massachusetts governor.

The former House Speaker refused to recant his accusations that Romney is lying about his ties to the organization behind the ads when asked by moderator David Gregory.

Read more on The Hill's Ballot Box blog.