Well, it seems that George W. Bush has outlasted one of those against him. Cindy Sheehan has quit. Apologies for the link to DailyKos, but this is worth noting.
The Iraqi campaign of the Global War is one of those places where it is a contest of wills. If America stands fast, it will win. If it folds, then the global war on terror will be longer and bloodier, with an end that could be very rough.
America would win, but we'd have to deal with the fallout.