On Tuesday, April 29, Chad Hurley, the pup-faced 30-year-old CEO of YouTube, popped up on the Internet along with the

On Tuesday, April 29, Chad Hurley, the pup-faced 30-year-old CEO of YouTube, popped up on the Internet along with the mayor of New Orleans, the governor of Louisiana and an executive from Google to invite the 2008 presidential candidates to participate in a “town hall meeting” to be held on Sept. 18 at the convention center in New Orleans, where, 32 months ago, thousands sought refuge from the devastation of Hurricane Katrina.

In the YouTube clip, the image of a bridge spanning a broad, muddy river flashed onto the small screen as the boosters took turns talking about the vague parameters of the would-be debate.

A Google senior vice president promised an “online discussion” and “a real-time forum.”

An accompanying press release noted that the showdown might be televised. Or not.

“The Internet has opened up public dialogue in ways we never imagined possible,” said Mr. Hurley of YouTube.

Their invitation had the distinct aura of something that had not been fumigated by the relevant authorities; in the increasingly big business of televised presidential debates, it was not an invitation at all, but a challenge—to the candidates, the major television networks, and to that man behind the curtain, the Washington-based nonprofit called the Commission on Presidential Debates.

For the past 20 years, in the general elections, these three parties have determined who debates whom; who moderates; and where the debate is hosted.

And recently, New Orleans, Google and YouTube have all seemingly smarted from being excluded. Sure, they’ve teamed up with television networks before, to add if-you-must Webbish features to the highly rated run of primary debates. CNN worked with YouTube. MTV hooked up with MySpace. ABC partnered with Facebook. Somewhere along the way, questions submitted by homespun Web heads became all the rage, and a whole new crowd of media executives, like the Voice of God broadcasters before them, threatened to bloom into full-blown podium hounds. For a low-key nonprofit like the commission, that could be dangerous. The organization has maintained its monopoly over debates largely by capably brokering sensitive deals between the major TV networks, the candidates, and the Republican and Democratic party leadership. And by choosing moderators and questioners who are palatable to everyone. And that does not include what Time magazine, in its 2006 Person of the Year cover, called “You.”

It is not for lack of trying to deal directly with the commission and the networks that Google and YouTube are going commando. According to sources familiar with the situation, long before they gave up and went their own route, executives from Google (and its somewhat recently purchased video-sharing sibling YouTube) were the first digital pooh-bahs to push the commission about a potential partnership.

The tentative talks began in May 2007, when Bob Boorstin, a former speechwriter for the Clinton White House who now serves as a communications executive for Google, set up a meeting with the commission’s leaders in Washington, D.C. At the time, as part of their ongoing efforts to boost their companies’ profile in the nation’s capital, Google and YouTube execs were already working with CNN honchos to host what would become two well-received primary debates.

But Mr. Boorstin, a seasoned political operative, must have already been looking ahead to the general election. Presumably in order to make a splash in the fall, Google would have to win over Janet Brown, the executive director of the commission. But after the meeting, Ms. Brown remained noncommittal.

To wit: Early that summer, Ms. Brown hired Elizabeth Wilner, the former political director of NBC News, to help the commission research what was being done with the Internet in the primary debates. What worked? What didn’t? Who were the players?

That summer and into the fall, Ms. Wilner went on a preliminary listening tour of sorts, introducing herself and the organization’s mission to various Internet players. Along the way, she met with everyone from Yahoo! to AOL to Google.

In November, after months of sifting through applications from universities and institutions around the country, the commission announced it had chosen four sites for the 2008 general-election debates: Hempstead, N.Y.; Nashville; Oxford, Miss.; and St. Louis.