It comes right at the end of the piece in the wake of Santorum's wins in Mississippi and Alabama, right about the 3:10 mark:
Look, Mitt Romney has said... his campaign has said that it would take an act of God for him not to be the nominee. Usually, a campaign with divinity on its side would be doing better than they are tonight.
Translation: he's not a Christian, he's a Mormon heretic.
Since the whole point of dog whistles is to inflame someone's prejudice without actually naming the prejudice, and that Romney's biggest weakness will be his difficulty in getting the GOP's evangelical base to muster any enthusiasm for him at all, it's nice to see the Obama campaign is already locking and loading their anti-Romney attack lines.