Yes, but I think the rhetorical battle over Sup Court appointments is one that can be won by Conservatives.
I have yet to hear Bush, or any of his talking heads for that matter, point out the hypocrisy and disingenuousness of Kerry's position on gay marriage. Bush should point out how its easy for him to say the things he says because Kerry knows that the Courts will do for him what he can't do in the political realm.
At the very least, Bush could rhetorically ask, "Since Sen Kerry claims to support letting the states decide, then it begs the question of what the Senator would do IF the Courts in fact do impose gay marriage or civil unions on the states.
The GOP should try harder to point out that Conservative, strict-contructionist judges would leave the resolution of these hot-button issues to the people, they wouldn't impose anything on anyone, whereas Kerry's judges would act like kings and remove the people from the process altogether.
Plus, Bush didn't even point out how Kerry voted against the federal DOMA which stated that states don't have to recognize gay marriages from another state. Over 80 senators voted for that, but not Kerry.
Kerry's already made his position clear on gay marriage, though. He's opposed to it, but won't stop it. He's repeatedly said that "We have a Constitution" when asked about it. That means he thinks there is a constitutional right to gay marriage, and he's not going to change his view. I think that this issue is already factored into the polls and will be reflected in the vote. No one is going to change their minds by Bush making an issue of it, at least no one will change their minds and vote for Bush. It's quite possible that no one will change their minds and vote against him because of the issue, as well, but he doesn't want to chance it.