Tuesday night's Democratic debate fell into a familiar pattern: a discussion of the relative merits of single-payer health care vs. a public option early in the evening, a few awkward exchanges thereafter but no single revealing moment, and a silly closing question that inadvertently revealed the extent to which television anchors tend to regard their viewers as simple-minded and allergic to substance. Anyone who hasn't already been paying attention to the race could glean some information from the dynamics on display: Warren and Sanders are running as transformational idealists; Biden, Buttigieg, and Klobuchar are running as art-of-the-possible realists; and Harris, Booker, and Castro are trying to split the difference. Warren was the target of criticism from multiple rivals (though, interestingly, not from Sanders), reflecting her status as a candidate on the rise in the polls.
But most of the audience tuning in for a three-hour debate held more than three months before the start of the primary season presumably knew most of this information already, or would have gathered it soon enough from other sources. Despite all the hype that debates receive—and despite the power that the qualification rules now hold over candidate behavior, especially fundraising strategies—the value that they actually add to the nomination process remains very difficult to determine. (I suspect that their net effect in general is somewhat negative, increasing the chance that the election is affected by non-substantive "zingers" and "blunders" while attracting an excessively large field of also-ran candidates seeking national publicity.)
Maybe the solution is to have fewer debates. But, at the minimum, expectations for their newsworthiness should be lowered to an appropriate level—especially in this election. With so many candidates in the race, it is hard for any single contender to receive enough camera time to make a strong impression or create a dramatic moment. And a multi-candidate election also scrambles the strategic picture considerably: attack one opponent, and another rival might wind up benefiting more than you do.
After every debate, complaints pile up at the feet of the moderators or the sponsoring media outlet: it was boring, the questions were bad, important topics were ignored, this or that candidate got too much or too little attention. Some of these points are always valid. But when debate after debate fails to enlighten, perhaps the flaw is in the institution itself, or in the anticipation that precedes it. Presidential candidates always differ in important ways that an informed electorate should consider before making its choices. But there's no reason to assume that debates, at least as they are currently organized, do much to educate voters about these differences.