Reply #7: McCain's concern for his political future surpasses his dislike for Bush.

[elperromagico]

I would imagine McCain is worried that he would lose influence in the Senate if he backed Kerry or didn't endorse Bush. Even if Kerry wins - even if the Senate remains Republican - you can bet Bill Frist would do everything he could to teach McCain a lesson.

Also remember that McCain's up for reelection this year. I could be wrong, but an endorsement of Kerry might affect his support in the Republican base in Arizona.

It's different with someone like Zell Miller, who is in a position where he can pretty much say what he wants and not face consequences; he'll be out of office next year. And he could probably still win reelection in Georgia if he wanted. Sad but true.