Gallup's latest results, polled between Tuesday and Thursday, days dominated by the controversy over the "cancer" add show Obama's approval ratings moving down 3 points and his disapproval rating moving up 3. 51% of voters now disapprove of Obama and only 43% approve. Romney's support edged up 1. Gallup shows the race tied at 46%.

A six-point swing in approval ratings is pretty significant in a moving average. Rasmussen also showed Romney gaining strength mid-week, moving into a 4 point lead over Obama. This is significant, because they are the only two pollsters who were polling throughout the controversy.