The decision makes a lot more sense if you consider the logic of the decision rather than thinking of it in shallow political terms.
The current occupant of the office has demonstrated that even a crackhead can be elected POTUS. There is no longer any honor associated with that position, just a lot of raw power.
Claiming her actions are somehow stupid is as silly as saying Jesus was a failure because he didn't overthrow the Roman oppressors of Judea and went meekly to the Cross.
This is her Jesus moment. Everyone will hate her for it, but future generations will look back and see it for what it really was. And you will be ashamed.
Oh, I'm sure there is a good reason behind her decision. My guess is that she is signing a HUGE book deal which will give her a good platform to articulate her political and social philosophy and set up to run for POTUS in 2012.
At worst she will fail in her POTUS run, But she will be a multi-millionaire.