Here’s a good piece by Dan Gillmor, on the credibility of fraudster Andrew Breitbart, which has risen in the wake of the Anthony Weiner scandal — to zero: Andrew Breitbart and the unwilling suspension of disbelief.

The entire Weiner affair has shown the worst of American politics, culture and media. Hypocrisy and mendacity abound, and have crowded out vastly more important issues from the attention they deserve. But the case also helps illustrate the evolving nature of credibility in media, especially in a “digital age”.

I was one of the doubters in this case, and said so in several places, including this column, where I called it “doubly suspicious given that it was first reported by a rightwing website run by a man who’s notorious for spreading misinformation”. Indeed, the doings of Breitbart and his allies have led any reasonable observer to strongly doubt the accuracy of what they say.

Getting it right in this highly visible case does improve his record. But do I consider him credible? No. In fact, I believe he’s merely raised his credibility to zero at this point.

How can someone raise his credibility to zero? By having negative credibility in the first place.