Because we have not yet made the political gains that need to be made as a result of the military victory.
The political gains need to be made ... in the United States of America.
Perhaps, but all that needs to happen is for Bush, Petraeus, or even Maliki to declare victory.
I think McCain might win in a landslide if he campaigned this summer leading up to the nomination, from Iraq. The press would have to follow him to every stop, and at every stop the heaviest un-stated question on everyone's mind would be "Where is Obama?"