To sum up...

In an email to me, Noumenalself summarizes what he thinks the difference between a Bush Presidency and a Kerry Presidency would be, namely Bush would make things worse, long-term, by entrenching religion into the government, and he lulls America into a false sense of security, by making us think that he's fighting a war against our enemies, when he isn't. Noumenalself has argued [I, II, III, IV] that fighting a half-assed war may make things worse than no war at all, and I agree. We don't see much of a difference between them in short-term policy. I would also add that the other difference depends on who loses. To wit, will the major opposition and dissent come from the Right or from the Left? In "The Moratorium on Brains" [The Ayn Rand Letter, Vol. 1, No. 2 October 25, 1971], Ayn Rand addresses this point:

"It used to be widely believed that the election of a semi-conservative (a 'moderate') is a way of gaining time and delaying the statist advance. President Eisenhower proved the opposite; President Nixon proved it conclusively. Their policies have not delayed, but helped and accelerated the march to statism. A major reason is the silencing and destruction of the opposition. If Mr. Nixon's program had been proposed by a liberal Democrat, the Republicans would have screamed their heads off—either on some remnant of principle or, at least, on the grounds of narrow party interests. But when total economic controls are imposed by a Republican President—in the name of preserving free enterprise—who, among today’s politicians, is going to protest and in the name of what?"

I believe that the exact same principle applies to foreign policy as well as domestic.