To be honest, He needs to do something to increase his odds and gain support from the far right. I will be voting obama, but I think the only way to give obama a run for his money is for mccain to pick romney.
However, he still has to deal with the huckabee problem. All of my "politically religious" friends like huckabee and don't like romney. Although
I guess they might rally for a romney.