There’s no shortage of New Yorkers being mentioned in connection with the 2008 presidential campaign. Democrats have Senator Clinton as their front-runner. Republicans have Mayor Giuliani, who is showing respectably in the early polls, and the often underestimated Governor Pataki, who has been visiting Iowa and New Hampshire. But there is a fourth potential candidate, not much mentioned, who in a way is as logical a presidential contender as any of the other three. That is the mayor of New York City, Michael Bloomberg – and despite all his protestation about how he wants to spend his post-mayor years giving away his money (which will no doubt take him a while), we are not counting him out.

This is not an endorsement, but neither is it a discouragement. It is true, no doubt, that the mayor would have a tough time as a Republican, given his tax increases, his campaign for gun control, and his support of abortion rights, which extended to opposing the confirmation of Chief Justice Roberts. The strengths he would bring to a Republican ticket – ability to reach across traditional divides and gain support in such traditionally Democratic constituencies as women, Jews, blacks, Hispanics, city-dwellers, Catholics, and registered Democrats – are available in one way or another from Messrs. Pataki and Giuliani and Senator McCain.

But what about the possibility of Mr. Bloomberg running as a Democrat? That’s where things get to look interesting. Compare him to the senatorial Hillary Clinton, who has an Article One personality and would be unlikely to attract much in the way of crossover votes from Republicans. Polls now show her losing to Senator McCain. Mr. Bloomberg, in contrast, has a true Article Two personality and would likely draw some support from Republicans and independent voters who admire his success as a capitalist and his record as a crime-fighter and efficient public administrator in New York. If he got the Democratic nomination, he would have a better chance than Senator Clinton of winning the general election.

Because of his immense personal wealth, moreover, Mr. Bloomberg would be able to break free from the regulations against campaign speech by using his own money to purchase ads and the like. So he wouldn’t be beholden to the traditional constituencies – trial lawyers, public employee unions – that prevent Democratic nominees from winning support from mainstream America. Age is no obstacle: The mayor turns 64 on Tuesday, February 14, which makes him about six years younger than Mr. McCain. And to judge by his bearing as mayor of New York, he’s fit and rarely at a loss for energy or spirit. He’s made a point of riding the subways, rarely moving around in imperial motorcades, conducting himself with modesty.

Then there’s the possibility that Mr. Bloomberg would run not as a Democrat or as a Republican but as an independent. But why would Mr. Bloomberg do it at all? Why would a billionaire many times over want to spend all that time traipsing around Iowa and New Hampshire instead of relaxing at his home in Bermuda? Watching Mr. Bloomberg, we get the sense he’s come, as mayor, to enjoy his encounters with ordinary New Yorkers at diners and Chinese restaurants in Queens and Staten Island and Brooklyn. Like all successful politicians, he derives energy and information from these encounters. And he’s an Eagle Scout with a dedication to public service.

While we’re not endorsing Mr. Bloomberg for president, he does represent the direction the Democratic Party has to move in if it is to regain control of the White House, the Senate, or the House of Representatives. He strikes us as more of a 21st century figure than are the other candidates, particularly Messrs. Giuliani and Clinton, who seem like creatures of the 1980s and 1990s. And we don’t put a lot of stock in the mayor’s protestations that he’s not interested. “I think at my age, I’ll be very happy to spend the next four years in the city, working for this city. I have no interest in running for governor,” the mayor said just before he was re-elected last year. “I’ll send my mother a copy of a letter that suggested I had an interest in running for president, which I don’t. She’ll be very pleased that anybody even mentioned my name.”

When Mr. Bloomberg first was mentioned as a mayoral candidate, people thought it was a far-fetched idea. But he won, defeating two Hillary Clinton-like Democrats – Mark Green and Fernando Ferrer – along the way. Mr. Green was like Mrs. Clinton in his grating self-righteousness, while Mr. Ferrer was like Mrs. Clinton in the sense that his “first Hispanic mayor” pitch is like Mrs. Clinton’s “first woman president” appeal. The Bloomberg 2008 presidential campaign is now at the stage where it is thought similarly far-fetched. As the idea builds momentum, remember, you heard it here first.