Ezra Klein says it so perfectly that I quote him in full:
With the Schiavo memos proven to be from a Republican source and Powerline not apologizing for their truthless innuendo and slander, it’s time to break out the popcorn and see if Big Trunk and Hindrocket can clear the shark. Odds are on massive carnage, but they might just end up laughing stocks. For that, see August Pollack on "Powerline-was-completely-fucking-wrong-gate" (Best. Gate. Ever.). It’s not just that they have no shame, it’s that they once met shame on a street, beat the shit out of him, rolled him up in a carpet, and threw him off a bridge. And don’t even ask me about the nightmare they put truth through. To paraphrase Marv in Sin City, after what they did to poor honesty, hell must have seemed like heaven.
Powerline, we must begin to understand, has no fucking idea what they’re talking about at any given moment. Once upon a time, some GOP operative sent by the Ghost of Nixon got something right for them in the Free Republic comments section, and ever since then the homo-erotically named bloggers over there have thought his success their own and tried to get a bunch of other Important Stories About Treasonous Democrats right too. But they don’t. Reading their site is like watching a blind child in a dog park — you keep trying to warn him not to step in the piles of shit, but you’re never able to get there quite quick enough. They want to make a point on Carter and end up calling him a traitor — ooh, all over your shoe! They want to attack the AP but end up proving themselves utterly ignorant of how cameras work — damn, you got it on your sock! They try to accuse Democrats of faking the Schiavo memo until an aide to current Republican Senator and Bush’s former HUD Secretary Mel Martinez — Agh, it’s all over you!
They get nothing right. Their fact-checking skills are atrocious. They neither report nor call experts, it’s just whatever they invented twenty seconds ago. Watching them work is like attending a high school debate match in the impromptu event. Arguments are created on the fly, accuracy is unimportant so long as the product accuses the "MSM" or Democrats of some cardinal sin that’ll leave Powerline’s sycophantic readers moaning with the exquisite pleasure that comes only from having one’s biases expertly stroked. The plausibility of their claims ranges from pathetic to laughable (has Big Trunk debated PZ Myers on the biological uncertainty of evolution yet?) and their traffic and credibility is entirely predicated on the work someone else did, success they’ve been totally unable to replicate. They have failed.
So enough’s enough — can we please stop taking them seriously? They’ve exhausted their purpose, which was proving that the blogosphere isn’t self-correcting and, in fact, offers rich rewards to opportunists with a polygamous relationship to the truth. Powerline’s not useful anymore. They’re not funny, like Glenn, or intellectually interesting, like Tacitus (old school Tacitus, anyway), or rhetorically talented, like Sullivan. They’re just there, hopping up and down and begging someone to take their latest theory — thought up seven seconds ago on the can — seriously. Don’t oblige them.