Photo: Jewel Samad/AFP PHOTO

It’s hard to figure out just how the first presidential debate turned into such an overwhelming political debacle for President Obama. After the debate, I thought Romney won, but the contest was closer than the already solidifying consensus held. Dave Weigel later observed, “the first presidential debate has come to remind me of Star Wars Episode I: The Phantom Menace. Democrats walked out of the theater/turned off the TV saying ‘huh, well, I wanted it to be better.’ After a few days of talking to friends, it changes from a disappointment into the worst piece of crap in human history.”

But why did that happen? How did a debate in which Obama missed numerous opportunities but still landed some solid blows devolve into the worst piece of crap in human history? Of course, I’m biased, and I may well have been listening to Obama’s uneven performance, filling in the missing details of his policy digressions that he failed to spell out. I’m also not that great at filtering debate answers through the prism of undecided voters. I remember watching George Bush’s famously disastrous 1992 town hall debate, where he attempted to answer a muddled question about how the national debt had affected him personally, and thinking he did a pretty good job trying to answer a question that made no sense:

But another possibility is that political reporters, largely through social media, converged on a shared and exaggerated reaction that became magnified. E.J. Dionne fingers the role of Twitter:

As the first presidential debate went on, the feeds of progressives went almost silent. After the debate, Obama-leaning commentators might have been even more critical of his performance than neutral analysts were. The negativity built and metastasized to the point where Obama’s “defeat” looked far worse 24 and 48 hours later than it did at the time. To invoke a football metaphor, it would be as if postgame commentary had the power to spin a 24–14 defeat into a 38–3 catastrophe. That can’t happen in sports, but it can happen in political debates.

It certainly sounds like a plausible hypothesis. It seem as though a seismic wave of panic and demoralization spread out from the liberal elite during the debate and continues to wash over the campaign.

I’m not precisely sure what the answer to this is, or if there is one. Kevin Drum fingered “the hack gap,” which in this case means the greater level of movement discipline among opinion commentators on the right. The answer is surely not for liberal journalists to act like hacks. (My job is to describe reality as I see it, not to shape arguments toward the goal of helping bring about political outcomes I’d like.) But maybe liberals who are not obligated by professional journalistic norms — activists, people who care — ought to be more mindful that hysteria is socially contagious.