I like Gordon but his grasp of numbers here is shaky. If 2% of voters say they are voting for candidate A but vote for candidate B, it would change a 52-48 victory for Candidate A to a 50-50 tie. It won’t make an eight point swing (52-48 to 48-52).
It's even worse than that. His statement was "If only two percent of those saying they will vote for Obama . . ." which means one percent of voters, or a shift from 52-48 to 51-49.