As to those two sentences: While I disagree with Sullivan, I do understand his point. The obsession of many of my fellow Clinton opponents was not always pretty. There were several friends who I found myself largely avoiding because their obsessions with Clinton were such that they could think (and talk) of nothing else. Worse, this knee-jerk single-mindedness often led to errors of political and legal judgement. Clinton and his allies played these tendencies to their advantage. As the Clinton haters became louder and more strident, Middle America walked away in disgust. It's sad, but it's also true, and Sullivan captures that attitude in those two sentences.
The good news is that the shoe is on the other foot now. The anti-Bush people (including my ex) have made themselves so ridiculous in their stridency and hate that they have become completely marginalized. No one pays attention to them and, when they do, the result is usually the opposite of what they intend. There's a good object lesson here: hate and unrestrained anger never advance an agenda, however just that agenda may otherwise be.