For Bush, I think the defining moment of his Presidency can be found here:
"And it's one of the wonderful -- it's like earning capital. You asked, do I feel free. Let me put it to you this way: I earned capital in the campaign, political capital, and now I intend to spend it. It is my style. That's what happened in the -- after the 2000 election, I earned some capital. I've earned capital in this election -- and I'm going to spend it for what I told the people I'd spend it on, which is -- you've heard the agenda: Social Security and tax reform, moving this economy forward, education, fighting and winning the war on terror."
Social Security reform? Dead.
Tax Reform? Dead.
Economy moving forward? On life support.
Education? Dead.
Fighting the war on terror? Oh, that's alive...if you assume that Iraq is the war on terror, but I'd count that as dead as well.
Winning the war on terror? Aborted.
More on the implications of this at Simply Left Behind