The other side of John Sides' debate skepticism

Those of us who've enjoyed the blogging and tweeting of political scientists in recent years often tease them as the "nothing matters" crowd. As measured by polling, in the normal course of things, gaffes don't matter, campaign ads don't matter...usually even gender doesn't matter.

As for debates...the ur-text for data-driven skepticism about their impact is John Sides'  Do Presidential Debates Really Matter?, published in September 2012.  The subtitle gives you the rhetorical thrust: Remember all the famous moments in past debates that changed the outcome of those elections? Well, they didn’t.

As a preview for tonight's debate, Sides offers an update/recap.  On the skeptical side of the ledger, here are the takeaways:

1. See subtitle to the 2012 piece.
2. Measurable debate effects on polling often fade.
3. Effects of one debate are often canceled out in later ones (e.g., Reagan in '84, Obama in '12).
4. Debate effects can't be easily separated from effects of other things going on at the time.
5. Debates are not likely to be decisive.

Thus Sides leads with, and emphasizes, debunkery. He also, however, acknowledges:

1. Debates can move the vote a couple of points, hard though the effect may be to determine. At best, debates provide a “nudge” in very close elections like 1960,1980, or 2000." That's not a bad "best"! In fact, Sides cites a study finding that in 2000, after all of the debates, "Gore’s poll standing was about 2 points lower than it was before." That seems a tad consequential.
2. A debate's effect on voters may be shaped more by ex post facto media judgments than by voters'  unfiltered real-time impressions.
3. Media impressions are now in large part collectively shaped in real time by Twitter.

Thus, while John Sides' daytime message might be "the debates probably won't matter," my night-mania takeaway is the right tweet can swing the election. You know, "for want of a horse", etc. In reverse.

Ergo, while a purist like James Fallows may advise us to watch the debate on C-Span, unfiltered, or even watch the debate with the sound off, my mind is made up:

I'm going to be tweeting my brains out.