They had a debate in Philadelphia last week and Mike Gravel wasn’t invited.

Now if you were planning a Democratic presidential debate, you might be forgiven if you actually forgot to invite Mr. Gravel. He’s a former senator from Alaska and he’s running for president, but he’s raised almost no money and polls show he has almost no support. NBC left him off the roster for its debate and, in so doing, raised a vital question:

Do forums like televised debates better serve the public if they include only those most likely to win a presidential nomination, or if they include lesser-known candidates who often are more provocative and less programmed than their better-financed rivals?

Mr. Gravel may be a peripheral presidential candidate, but his role in American history can more nearly be described as heroic than peripheral. It was Gravel who inserted into the Congressional Record thousands of pages of documents that now go by the name of the Pentagon Papers. For that act, journalists and historians will always remember him as a pathfinder and a patriot, though there remain many who consider the Alaskan’s decision to defy the Nixon administration a traitorous act.

Debating debates

We’ll leave that debate to the historians. We have our own debate, or rather our consideration about how to conduct debates, to ponder. And in some ways that debate comes down to efficiency and electability vs. eccentricity and egalitarianism.

It’s surely more efficient to pare the field for a debate, especially in election seasons like this one, with so many candidates, so many of whom have such meager prospects. But is it fair to those who are spending the year traveling across the country and pondering serious questions, and is it fair to members of the public, who may hear more sense from the more obscure candidates than they do from the ones who, with the assistance of image consultants and pollsters, have more polished presentations?

And then if you do decide to present a smaller, more manageable panel of candidates, how do you make the distinctions? By the amount of money the candidates raised, which is why Mr. Gravel was dropped from the list? By some other, less quantitative means?

You might not, for example, leave off Bill Richardson because he is a governor and former diplomat and thus by any meter of accomplishment deserves a hearing. How about Christopher J. Dodd and Joseph R. Biden Jr.? They’re bigger long shots than Appalachian State, but maybe you include them because they are sitting senators with important committee assignments. Then there’s Dennis Kucinich. He’s been elected to the House six times and was a big-city mayor.

This, as you can see, is a mess. Because as you go down the list, you continue to find reasons to keep candidates on the stage (and, to paraphrase the Rev. Jesse L. Jackson, himself a former presidential candidate, to keep their hope alive), and then you end up with a series of lecterns that makes the stage look more like the GE College Bowl than like something that leads to the Electoral College.

Money doesn’t talk

Last week’s exclusion of Mr. Gravel prompted a series of newspaper advertisements from Gregory Chase, a Gravel supporter in New Hampshire who charged NBC with “censoring a multi-term United States senator, a veteran and a patriot.” Mr. Chase offered to give NBC $1 million in advertising or in just plain cold cash in exchange for an invitation for Gravel. The network didn’t bite.

So Mr. Gravel was excluded – unlike a poverty activist from Hartford, Conn., named Ned Coll, who ran for president in 1972 and was included in a New Hampshire debate along with Sen. George S. McGovern of South Dakota, Sen. Edmund S. Muskie of Maine, Sen. Vance Hartke of Indiana and Mayor Sam Yorty of Los Angeles. Mr. Coll is remembered for having brandished a rubber rat during the debate – a moment that still is considered one of the low points of New Hampshire political history – but he used the moment to bring attention to what he argued was the principal issue in the election, urban poverty (never mind the Vietnam War).

“The scariest thing is to be up there and to be close to the other people who are running for president and to see that they are clones,” says Coll, who is running for president again in 2008. “These debates diminish ideas rather than raise new ideas, and that’s why the presence of people like me is a challenge to the other candidates. The rat thing may have seemed unusual, but it got poverty onto the front page of newspapers across the country.”

Ideas are lost

Mr. Coll made a spectacle of himself, but he also makes a good point. And fringe candidates belong in debates – to a point.

It’s true that having people like Mr. Coll – and Morry Taylor, the wheel and tire executive who joined debates in Iowa, New Hampshire and South Carolina in 1996 – on the podium is inconvenient. But inconvenience is the price of democracy. “I at least asked questions no one else would ask,” Mr. Taylor says now.

But it is also true that the stakes in presidential elections are so high that the country can’t afford many distractions in the serious business of making political choices.

So perhaps the way to go is to keep presidential debates open to the mice (and rats) of the lower-tier presidential candidates until three or four months before the primaries and caucuses begin, giving them a chance to air their views and perhaps to catch air and take off. But after that, serious people have to make serious choices – and one of the choices they have to make is to differentiate among the candidates, and that means limiting debates to the people who have a chance to make a difference.