Can Paul Ryan boost Romney's poll numbers?

A new POLITICO/George Washington University Battleground poll released today finds that President Obama and Mitt Romney are tied in a dead heat for the White House. The poll, which was conducted a few days before Romney announced Paul Ryan as his running mate, finds that despite the unprecedented amount of money being poured into the contest and the non-stop attacks from each side, the top line numbers are essentially unchanged from a previous Battleground poll in early May.