Romney’s parries have been completely factual and delivered in a confident and collected fashion. How much you want to wager on Trump being factual, confident and collected as opposed to exaggerated, blustering and strident?
He either has something or doesn't - we'll see. This is likely in coordination with the RR team.
And beside, I don't care if Trump has anything of evidence about that lying Obama because he is still jerking Obama's chain. Obama should own a cemetary for all his hidden skeletons.