What Was George W. Bush's Biggest Mistake?

Prominent neoconservative Jennifer Rubin's answer is emblematic of a widespread failure to grapple with his tenure and legacy.

Almost four years after George W. Bush left office, neoconservatives still haven't grappled with his worst failures, as Jennifer Rubin reminds us in the clip above. Asked to name Bush's biggest mistake, she offers two answers: (1) "His failure to forcefully and promptly reply about the scurrilous allegation that he lied about weapons of mass destruction in Iraq;" and (2) his choice at the beginning of his second term to pursue private Social Security accounts before immigration reform. As I see it, the Bush Administration was constantly avowing that it didn't lie about pre-war intelligence, and immigration reform was unlikely to pass regardless of when it was attempted. But the larger problem with these answers is the notion that Bush's political mistakes were more grave than the numerous substantive errors that he made while in the White House.

I understand Rubin doesn't agree that the Iraq war was a catastrophic mistake. But even someone with her neoconservative worldview should recognize all of the following as grave errors:

1. The failure to take terrorism more seriously prior to 9/11.
2. The failure to heed the expert planning that ought to have guided the American presence in Iraq after the initial invasion.
3. The failure to bring Osama bin Laden to justice. 
4. The failure to address the deficit -- indeed, the pursuit of policies that made it substantially worse.
5. The failure to address the economic conditions and regulatory policies that ended in the housing bubble and financial crisis. 
6. The failure to institute safeguards that would have prevented the morally repugnant and strategically catastrophic prisoner abuse scandals. 
7. The failure to institute safeguards that would have prevented so many innocents from being thrown into the prison at Guantanamo Bay.
8. The seven years spent in Afghanistan without much to show for it. 
9. The attempt to appoint Harriet Miers to the Supreme Court.

My own list of Bush Administration mistakes is much longer, but even controlling for the dramatically different ideological perspective of neoconservatives, Rubin's picks betray a profound failure to grapple with a presidency that needlessly weakened America in multiple ways.