Michael Griffin's job
as HE himself sees it is to get the shuttle replacement (Ares) on track by 2009 with the kind of momentum that it could not be shut down without great political cost. He is going to give any future administration a spacecraft that has the ability to go beyond earth orbit; to the moon or neo's or even mars. Whether a future president has the will do use that capability is another issue. At least the ability will be there.
John Edwards has said a lot of positive things about the vision. Not sure if he plans another run.