The name of the game in the fall campaign is to get your own voters out to vote for you. It's not a contest involving voters who can go either way. They all go one way, or no way.
You have to win the ideological contests during the years between elections.
Romney and McCain both forgot to get Republican voters out to vote. In the end they both got about the same number of votes ~ give or take half a mil ~ trivial in any election with 125 million voters!
Romney got out the vote. The votes were stolen.