So Anthony Weiner is resigning, after discussions with his wife persuaded him he could no longer serve. He was facing the prospect of an ethics investigation, and House leaders were set to strip him of a key committee slot, both of which would have compounded his humiliation.

Weiner can be described, I think, as Twitter’s first major political casualty, in several ways. For one thing, no other equally high profile elected official has had to resign because of a scandal set in motion by a single Tweet. For another, it was the lack of experience with Twitter-sparked scandals that led him to botch his initial response to the unfolding story. He claimed the underwear bulge picture had been Tweeted from his account by his hacker. He was navigating the largely uncharted technological waters of Twitter-based scandals, and as a result, he badly screwed up. In the future, politicans who get in trouble over a wayward Tweet wiill look back on Weiner’s travails as a guide on what not to do. Weiner, alas, had no such playbook at his disposal, and he compounded his problems at the outset.

Weiner was Twitter’s first major political casualty in a darker way, too. This eposide demonstrated in a unique way that Twitter can encourage pack political journalism at its worst. I’m not defending Weiner. He lied to his colleagues, and what he did was unspeakably foolish, given that his outspoken liberalism guaranteed that he’d be a tempting target for the right. I’m agnostic on whether he should have resigned; other public officials who have committed far worse acts, sexual and otherwise, haven’t faced a fraction of the pressure he faced to step down. But ultimately, all you can say about his departure is that Democrats have now lost a very effective spokesman for the liberal cause — even if at times he did disappoint — and his profound folly and subsequent humiliation are just sad.

But look — even if there’s no defending Weiner, you can’t escape the fact that the weeks-long journalistic obsession with his lewd acts was a profoundly dispiriting spectacle on many levels. And Twitter played a major role in encouraging it. There were times during this whole saga when the swarm of prurient and even adolescent Tweets about Weiner coming from reputable and established journalists and political observers was simply impenetrable. At times a kind of echo effect kicked in where it was clear that if you Tweeted about any other topic, it would rapidly get drowned out. At one point a journalist colleague joked to me that he may as well take the afternoon off. His meaning was clear: Twitter has become a kind of de-facto front page for political journalists, and if he reported and Tweeted on any other topic, he could count on it getting completely lost.

No, Twitter is not ultimately to blame for what happened, and Weiner very well may have ended up getting forced to resign without it. And again, there’s no defending him. But this episode also showcased and encouraged a new kind of hyperkinetic, Twitter-fueled pack journalism that at bottom was very, very ugly to behold. And I hope I’m not the only one who’s deeply uncomfortable about the way it all unfolded.