NORTH CHARLESTON, S.C. -- Candidates' attacks, gaffes and memory lapses have dominated coverage of the 21 Republican debates so far, but reporters are covering the wrong people. The real story isn't on the stage; it's in the audience.

That will never be more true than Thursday night, when CNN stages the 22nd debate from the North Charleston Convention Center in South Carolina.

Newt Gingrich will almost certainly be asked -- maybe at the top of the two-hour broadcast -- about his tortured marital history, especially about an accusation from second ex-wife Marianne Gingrich that the former speaker had asked her to accept an "open marriage" so that he could continue a long affair with the woman who is now his third wife, Callista.

As soon as that question is asked by CNN moderator John King, the audience will have its moment -- and its power.

The audience of 1,500 will comprise members of the Southern Republican Leadership Conference and Tea Party Patriots, as well as state and local officials from South Carolina. Expect them to boo lustily -- and to amplify an already loud theme in conservative and Republican circles: that the "mainstream" media is against them. Gingrich, a master of media bating and bashing, has risen in the polls partly on the strength of that notion.

The long string of debates have shown viewers a Republican Party in the raw, not in the words of the candidates but in the groans, boos, cheers and applause of crowds who blithely ignore halfhearted TV network admonitions to keep quiet.

The audiences have been loudly patriotic and enthusiastic about the campaign. But their outbursts have also uncovered a GOP id that cheers for Texas' vigorous use of the death penalty; cheers repeated attacks on the national media, even when it is embodied by Fox News moderators; boos at the suggestion that the federal government, not the states, should enforce immigration laws; boos at anything less than a send-them-all-back immigration policy; boos a gay soldier who asks a question about gay rights; cheers at the mention of waterboarding and torture as a means of interrogating terrorism suspects; and boos at an African-American reporter who asks repeated questions about race, poverty, inequality and racial stereotypes.

To a degree not seen since before the days of television (and the foundational Kennedy-Nixon debates of 1960), candidate debates are now a theatrical exercise, in which the Greek chorus of the crowd plays as much of a part as the give-and-take among the candidates and the moderators.

If Mitt Romney decides to duck out on next Monday's NBC-sponsored debate in Tampa, Fla. (the option was raised when it looked like he had an easy victory coming in the South Carolina primary), expect his aides to cite the raucous nature of the affairs as one reason.

"Even a few years ago it wasn't this way, I don't think," said Mandy Grunwald, a leading Democratic political consultant, whose clients included then-Sen. Hillary Clinton in 2008. "First, there weren't always audiences. And if there were, they would tend to cheer for their guy or gal, and that was about it. Nothing like this."

The changing role of the "mainstream" media is one explanation for the vox populi tone. Facing conservative suspicion, some networks decided to partner with Tea Party, state party or other grassroots organizations to stage the debates, and part of the co-sponsors' price was to bring along a partisan audience. (Thursday night's CNN debate is co-sponsored by the Southern Republican Leadership Conference.)

In an era of reality TV shows and other in-front-of-a-live-audience programming, a debate with an absent or silent crowd is also a tough sell, too sedate and silent for today's tastes.

And even by the standards of the recent past, this season's debate formats and candidate strategies seem to lead more inexorably to snappy sound bites designed to play to the crowd.

The result is more rowdy -- and revealing -- than perhaps GOP strategists intend or want, at least if they care about making an impression behind their hard core.

Here's some more discussion of what the debate crowds have had to say:

- Cheering Texas Gov. Rick Perry's embrace of the death penalty.

- Cheering the idea that an uninsured man should be left to die.

- Booing Perry's relatively moderate immigration stance.

- Booing when a gay soldier asks a question about gay rights.

- Cheering for waterboarding and torture.

- Giving Gingrich a standing ovation for rejecting moderator Juan Williams' comments on race.

Mollie Reilly contributed to this report.