You do realize there is a difference between a race between two non-incumbants running as insurgents in their respective parties and one incumbant running against an establishment pick, right?
McCain was ahead for the week before, after and during his convention, but that was really about it. Most of the rest of the time, he trailed Obama badly.
Romney has NEVER been ahead of Obama in the RCP average.
Which is true, McCain enjoyed a nice bump in the polls after the RNC even beating Obama, but this year isn't the case for the GOP.
For Willard to have barely a blip in the radar, while Obama is soaring in the polls after their respective conventions shows Willard is extremely weak.