Yesterday afternoon, in a small room two doors away from the lobby of Des Moines’ Iowa State Historical Building, two doors down from the mammoth’s skeleton that presides over that lobby, seven of the eight Democratic presidential candidates sat around a V-shaped table, talking with, at, and occasionally over one another. That’s right, kids: a debate.

So…who had the best rapport with the crowd? Which lines got cheers? Which lines got booed?

I have no idea; the debate took place without an audience, save for a few scattered campaign staffers, and was broadcast only via radio. Except for a few photos taken right before the event and posted on NPR’s Web site, I don’t know what it looked like. What I do know is that Hillary Clinton stands by her vote to call the Iranian Revolutionary Guard a terrorist organization. And that Joe Biden believes humanitarian interests must sometimes trump national interests when it comes to U.S. immigration policy. And that Mike Gravel favors giving aid to Hamas and Hezbollah. And that all seven candidates who participated (the full field, save Bill Richardson) aren’t the biggest fans of President Bush.

The radio-only debate is something of a fledgling tradition at NPR; during the 2004 primary season, the network resurrected the format when it hosted a debate for Democratic hopefuls—the first radio-only debate since Republican candidates Harold Stassen and Thomas Dewey faced off in 1948. The 2004 debate aired to much fanfare, and the reviews (generally, and almost) matched the predictions. (“We actually learned from the candidates on this one,” wrote the Dallas Morning News, without a hint of irony.)

Yesterday’s debate was no exception: when the radio stars kill the video, it seems, good things happen. The talk’s moderators—Steve Inskeep, Michele Norris, and Robert Siegel—selected three general topics for discussion: Iran and the Lessons of Iraq, Relations with China, and Immigration. The goal wasn’t breadth, but depth: “By covering a little less, we hope to go deeper,” Siegel noted. “We will try to have some real discussion here today.”

Mostly, it worked. The two hours of V-table talk featured as much substantive policy discussion as you could expect during a debate that takes place less than a month before a hotly contested primary. Which is great—though, at the same time, pretty boring. The New York Daily News, for example, led its debate analysis with a lament:

Democratic debate showdown: Hillary versus Barack. Let’s get ready to … snooze.

The first faceoff between Hillary Clinton and Barack Obama since she launched a scorched-earth campaign to take him down was no wrestling-cage match.

Instead, they had a soothing, civilized chat about policy.

That’s because the confrontation came at an NPR-sponsored Democratic debate. There were no YouTube snowmen. No cheering sections. No TV cameras.

The debate was dull? Sure, a little. Still, it’s snooze you can use: this is exactly the kind of substance we need to be seeing from candidates, both Democrats and Republicans—the kind that shows us not just what they think, but how they think (and in some cases, that they think). Taking the focus off convenient sound bites yesterday allowed some of the latter two to shine through: we got to hear candidates talking through foreign policy and immigration choices, answering the moderators’ provocative and relatively innovative questions at length. (But not too much length: as Rolling Stone’s Tim Dickinson put it, “the moderators could all teach Wolf Blitzer a lesson or two on how to reign[sic] in blabbering candidates and steer a discussion.”)

NPR cemented its this-is-about-substance point by fact-checking a sampling of factual claims candidates made over the course of the debate. NPR blogger Tom Regan live-blogged the event with an eye toward fact-checking; after the debate’s conclusion, other NPR reporters Michele Kelemen, Adam Davidson, and Jennifer Ludden did a retrospective fact-check of candidates’ responses—revealing, among other things, that Clinton had unfairly implied causation between the controversial resolution she voted for in September (Kyl-Lieberman, which branded Iran’s Revolutionary Guard a terrorist organization) and a recent, seeming decline of Iran’s support for Shiite militias in Iraq. And that Biden had “mixed up some numbers” when he said that 60 percent of illegal immigrants in the U.S. are non-Spanish speaking and have overstayed their visas. (“In fact, 60 percent of the undocumented population is believed to have crossed a border illegally; an estimated 40 percent came on legal visas and overstayed them.”)

Megan Garber is an assistant editor at the Nieman Journalism Lab at Harvard University. She was formerly a CJR staff writer.