Ok, this isn't necessarily what I think will happen, but I think it's not outrageous, so I'll give it anyway.
Here's the deal, the greatest gift ever given to conservative leadership was the Roe v Wade decision. Hands down, no doubt about it. I agree with the decision, but it really gave an easy bumper-sticker argument for conservatives. They get to attack it over and over, and it is truly the glue that binds the movement. Plus, it allows them to continue passing anti-abortion legislation written so that it will be voted against by "murderous Democrats" and overturned by "activist judges"; giving them a three-fer. In short, Roe v. Wade is a cottage industry for the cons, and they use it well.
Thus said, if Roe is overturned, the gravytrain is over and it's back to basics on many levels. Sure, there are other issues, and sure they can still milk abortion for some impact; but it's largely over. If the other issues were as powerful and influential, they'd be using them. But nothing matches the black/white impact of abortion with these people. And while there will continue to be minor skirmishes for many years, they'll have lost the main impact. Remember, if even a meager 5% of conservatives stop voting Republican, we've got the Whitehouse. And I suspect that Roe is a bigger vote getter than that.
And on top of that, many moderates lean Republican because they don't see them as being the loons that they are. And somehow, they don't see Roe as being an issue. But all bets are off if Roe is overturned. An anti-Roe judge would be a clear sign of where the Repubs really stand. Plus, it would outrage many libs and seriously motivate them. We don't have that now, because we won. But overturning Roe would change all of that.
So basically, an anti-Roe judge will slightly dampen Republican turnout, would lose them their best argument, and would mobilize fiery liberals and sway a few moderates. There can be little doubt of that, and it's enough to win the Whitehouse and perhaps a few seats in Congress too. This is Rove's worst nightmare.
My Half-Ass Prediction
And so here's my half-ass prediction: I think that Bush is going to pick a fiery hardline conservative who will eventually prove to support Roe v. Wade but be an extreme right-wing nutjob on everything else. Bush will pretend that he hadn't asked the nominee about his Roe opinion or wasn't using it as a litmus test, just as he claimed during the election. Or maybe they'll even be open about it, and say that they didn't want to divide the country; and that they're picking someone that matched O'Connor's Roe vote, so as to not overturn anything.
This would, of course, upset the hardline Social Conservatives, but what are they going to do about it? Vote Democrat? Hell, they'd be more likely to vote Democrat if Roe was overturned than if Roe was upheld due to a Republican. Besides, Bush isn't running for re-election, and the Republican Congressmen could suggest that they didn't like Bush's choice, and even try to pin it on "obstructionist Dems" and their dangerous grip on Washington. Again, the SoCons would be upset, but so the fuck what? It's better for Repubs than them being satisfied and not voting. Again, only a minor drop in voting would give us the Whitehouse.
So anyway, that's my prediction. They'll pick a pro-Roe judge who wreaks havoc on everything else. Without any doubt, the judge Bush picks will be an extreme economic hardliner. But there's no reason to assume that, besides Roe itself, that the judge won't be an extreme fundamentalist hardliner. Roe is the keyword, and if the replacement isn't anti-Roe, we won't be able to rally as much of a defense. So we could get nationwide voucher programs, federally-supported religions with no federal oversight, or whatever; and the media would treat him as a moderate. Of course, the SoCons will complain no matter what he does, as long as he's anti-Roe; but they'll forgive Bush, just like always.
Anyway, I'm not saying this is the most likely choice. I'm just saying it has a good possibility, so I thought I'd share it. And there's not a chance that Rove hasn't thought about it, so it's just a matter of how much they're willing to piss-off the religious right.