Bush wanted to make gay marriage a partisan election year issue, and it blew up in his face. Why? Because his advisors were political dumbasses who wanted to change the focus of this election in the most meanspirited way possible. It didn't work. All they've done is highlight the fact that Bush is a divider, not a uniter.
This will be a big issue in the debates and on Election Day... not gay marriage. Why? Because Americans are tired of their politics being so divisive. More people are scared of a government which is willing to enforce morality at the Federal level than are scared of what might happen if that gay couple down the street actually become an old married couple rather than just act like one.