I'm pretty sure Kuskovian is correct, and the United States will leave Iraq no matter who is elected.

Quote Originally Posted by Council on Foreign Relations
Q: What would or should we do if a sovereign Iraqi government asks us to leave, even if we are unhappy about the security situation there?

McCAIN: Well, if that scenario evolves, then I think it's obvious that we would have to leave. I don't see how we could stay when our whole emphasis and policy has been based on turning the Iraqi government over to the Iraqi people.
CFR quote

Nouri al-Maliki requested "a memorandum of understanding to put a timetable on their withdrawal" on 7/9. <link>

As everyone knows, Barack Obama has ran on a platform of a phased withdrawal, that he has reiterated as recently as 7/12, and probably won't back-down from that.

Once again, this is indicative of the normative, monolithic nature of American politics. Its just like Viet Nam; the Tet Offensive made the war unpopular, and the corporate elite decided to begin a phased withdrawal. This time around instead of the Tet Offensive, we have $4 gas. Americans can't possibly be made to give a fuck about anything but their rapidly devaluing currency right now, so anyone who made their way through the layers of ideological filtering to reach a position of political power will make the exact same politically expedient decision.