LOS ANGELES – When Democratic presidential candidates square off for a debate in front of CNN’s cameras tonight, don’t strain your neck looking for Wolf Blitzer, Christiane Amanpour or any of the network’s reporters. They won’t be asking the questions. Those will come from animated computer programmers, off-camera gay soldiers and guys in Viking helmets.

The debate in Charleston, S.C., airing live at 7 p.m. , will be the first among presidential candidates in which the questions are posed by actual voters submitting videos through the Internet – and journalists and politicians agree it won’t be the last.

“It’s here to stay,” University of Virginia political scientist Larry Sabato said. “You can’t put the toothpaste back in the tube.” Adds Jon Klein, head of CNN’s U.S. operations: “What candidate could walk away from a chance to hear from actual Americans? What candidate wants to look afraid to do it?”

CNN and video-sharing Web site YouTube.com began asking voters to post questions on the site earlier this month. As the deadline approached Sunday night, more than 2,600 had been submitted.

CNN and YouTube will also collaborate on a Republican debate on Sept. 17 in St. Petersburg. The Web site will begin collecting questions for that date at 9 p.m. today.

CNN came up with the idea earlier this year while pondering ways to inject some creativity into coverage of presidential campaigns, which once lasted less than a year but have turned into grinding, 18-month-long forced marches.

“We’re constantly trying to steer away from covering the election as a horse race and get into the issues,” Klein said. “What better way than to allow American voters to pose the questions?”

Actually, letting voters pose questions doesn’t always work out too well, as anybody who has covered early-season primaries in Iowa and New Hampshire – where campaigns consist mostly of visits to coffee klatches and small town-hall meetings – can attest.

Queries can range from the maddeningly broad (“You hear somebody say, “Senator, give us your thoughts on the U.S. economy,’ and you just drop your face into your hands,” Sabato said.) to the numbingly narrow. S.I. Hayakawa, running for the U.S. Senate from California, once infamously exploded at a question about a small town’s upcoming vote on greyhound tracks: “I’m running for the U.S. Senate. I don’t give a good god—- about dog racing.”

But CNN reporters who’ve combed through the submissions say that while there’s a lot of chaff, they’ve got more than enough wheat for a debate. “I had some fears when I first heard about this,” said Anderson Cooper, the CNN correspondent who will moderate the debate. “But once I saw the questions, I relaxed …”

All question videos can be viewed at http://youtube.com/contest/DemocraticDebate. Some, like the one from a man in Cedar Rapids, Iowa, who asks how the candidates can keep the Federal Reserve from inflating the U.S. money supply, sound little different than what you might hear on “Meet The Press” or any other Sunday-morning talk show.

Others, like the man wondering if high-performance sports cars should be banned, are peculiar. And some, like the man demanding congressional hearings on UFOs as he sings “I’m A Believer,” sound more like they came from “Saturday Night Live.”

Some are barely questions at all: A stuffed blue duck asks, “Do you feel the terrorists will come here?” before exclaiming, “Oh my God, there is one here right now!” as the camera goes jittery.

Others use visual gimmicks to make serious points. A question about the military’s don’t-ask-don’t-tell policy on gay soldiers comes from a disembodied, off-camera voice because the man asking it is a gay soldier. One about whether the war in Iraq is motivated by corporate interests includes a clip of President Eisenhower warning about the military-industrial complex. A cartoon character identifying herself as a computer programmer asks how candidates will stop high-tech jobs from moving off-shore.

If the cleverly staged questions were intended to catch the eye of CNN programmers, at least some of them worked.

“My favorite is the purring cat with the subtitle that asks, “How can you protect my food in the future?”‘ said Klein, who adds with a nearly straight face: “We’re really interested in that feline demographic – our ratings are low there.”

Whether the candidates will be amused at questions from faux Vikings and animated jobless people remains to be seen. Sabato, the University of Virginia political scientist, said the candidates need to get over themselves.

“The debates so far have just been terribly, utterly boring,” he said. “We could use a laugh or two.”

Sabato is an unabashed fan of the involvement of YouTube videos in the debate. “Hey, if we’re going to get more people – especially young people – into politics, we have to use the techniques with which they’re familiar, and that means YouTube,” he said.

In fact, YouTube is no stranger to politics. Most of the campaign organizations regularly contribute videos to the site: some plugging their own candidate, some apparently showing opponents flip-flopping on the issues. If you’ve heard reports that Republicans Rudy Giuliani and Mitt Romney have changed their stands on abortion, it’s largely because of YouTube video clips of their old speeches.

And YouTube may already have had a decisive effect on the presidential race when it became the home of a widely circulated video that showed U.S. Sen. Paul Allen, running for re-election in 2006, referring to an Asian-American man by a word that some of his opponents said was a racial slur. Allen, who if re-elected would have been a strong candidate for the Republican nomination this year, was defeated.

Expanding YouTube’s role in the campaign into a mainstream media outlet like CNN is part of journalism’s fascination with so-called “user-generated content” – that is, using new communications technology like cell phone cameras and Internet social-networking sites to involve the public in news-gathering.

Executives at Fox News, who are keeping a careful eye on the CNN debate experiment, say that even if it’s a dud, the citizen-journalist is a big part of television news’ future.

“Social networking and user-generated content are important phenomena right now,” said David Rhodes, vice president for news at Fox News, “and I think every news organization has to think about ways to incorporate those into what they’re doing.”

Video shot with passengers’ cell phones played an enormous role in Fox News’ coverage of the 2005 terrorist bombings in the London subway, Rhodes noted: “Those were some of the most dramatic pictures.”

Involving unvetted civilians in news coverage has its risks, especially on live television: Almost every news division has been burned by crank calls from Howard Stern’s legion of prankster shock troops that made it onto the air. CNN officials concede ruefully that it’s a possibility Monday, too.

“We’re checking the videos carefully,” said Klein, “but there’s always a chance that we’ve missed a flash-frame somewhere. This could be the first presidential debate where a nipple gets on the air.”