Is Howard Dean an updated version of George McGovern? Or, rather, the new John McCain? Is he the second coming of Bill Bradley or possibly Jimmy Carter? The short answer is, yes. He’s all four rolled into one — an insurgent who is taking on Washington, D.C., and his party’s establishment. [IMGCAP(1)]

That positioning explains why Dean is causing problems for the rest of the Democratic field. But it also exposes some weaknesses.

Like Bradley, Dean will tell you what you need to know regardless of whether you want to hear it. Bradley’s medicine tasted nastier than Dean’s, but both Democrats have appealed to the upscale, Range Rover-driving, Merlot-drinking Democratic crowd.

Dean is a much better speaker than Bradley, and his energy and emotion really drive a crowd. If Bradley had Dean’s personal skills and feistiness, he might have defeated Al Gore in Iowa or New Hampshire.

Unlike Bradley, Dean is running in a crowded field without a prohibitive favorite, not head-to-head against the sitting vice president. That means that the Vermonter needs a smaller piece of the pie than did Bradley. And, of course, Dean is a neighbor of New Hampshire.

Like McCain, Dean presents himself as a reformer who is taking on the political system. Neither man began his presidential quest as the favorite of his party’s elite, and Dean, like McCain, is wearing that fact as a badge of honor.

But Dean lacks McCain’s engrossing personal story and his enthusiasm for wooing the press. The Arizona Republican is an American hero and also a better schmoozer than Dean, who doesn’t seem to know when not to pick a fight. The former Vermont governor seems not to like reporters, while McCain always knew how to use them to his advantage.

Unlike McCain, Dean is running in a party that is more receptive to quirky outsiders. Republicans always seem to turn to the predictable choice who has the backing of party insiders, whether Richard Nixon, Gerald Ford, Ronald Reagan, George Bush (41), Bob Dole or George Bush (43). Democrats have been willing to flirt with — and sometimes even nominate — insurgents, whether Carter, McGovern, Gary Hart or Bradley.

Dean, like Carter, is a former governor who had little association with Washington, D.C., when he launched his White House bid. Carter was able to moralize about Washington’s problems just as Dean has been able to criticize the votes (especially on the war with Iraq) of his major Democratic opponents, all of whom have spent years in the nation’s capital.

And, like Carter, Dean is something of an ideological chameleon. Carter successfully avoided being pigeon-holed ideologically in 1975 and 1976, and Dean has transformed himself from a moderate (especially on guns and fiscal issues) when he served as governor to a liberal on the national stage.

In an approach reminiscent of McGovern, Dean is rallying the left wing of the Democratic Party in a fight to take on the Democratic Leadership Council for the soul of the party, and President Bush for the right to lead the country down a different path.

And Dean’s use of the Internet to raise cash and mobilize supporters seems akin to McGovern’s use of Alabama attorney Morris Dees’ direct-mail fundraising expertise.

Yes, Rep. Dennis Kucinich (D-Ohio) is winning some support on the left, and Dean’s record in Vermont has been criticized by Green Mountain State liberals. But Dean, who won the decidedly liberal MoveOn.com “primary,” is now being defined in the public arena by his positions against the war in Iraq, against the Bush tax cut and for civil unions. And he is being portrayed in the media and perceived by Democratic activists as a liberal.

So what are Dean’s challenges? First, because some of his early support stems from his perceived liberalism, his base could crumble when liberal groups and his Democratic opponents begin to paint a very different picture of the former governor.

More importantly for Dean’s chances, voters generally have not preferred candidates who seem as angry as the governor often comes across. Instead, they’ve been attracted to likable candidates who convey an inner strength and steadiness.

Carter’s religiosity and low-key style appealed to voters turned off by the political corruption of the early 1970s, while McGovern, a low-key Midwesterner who ran heavily as an anti-war candidate, outmaneuvered other Democrats who didn’t fully appreciate the party’s new delegate selection rules, the potential of direct-mail fundraising or the mood of the very unusual period.

And, perhaps most importantly, McCain and Bradley got stuck in head-to-head contests against establishment-backed candidates. Neither outsider could get over that hump. In contrast, both Carter and McGovern were nominated because they avoided getting into a two-person race. Each became a solid frontrunner for the Democratic nomination before the field had winnowed, and that helped both men win the backing of insiders who wanted to be on board with a winner.

So far, Dean has followed the road already traveled by Josiah Bartlett, the liberal, independent-minded president from northern New England in NBC’s “The West Wing.” Both men are popular with many Democrats because they appear to be fiery idealists who don’t live by polls but stand on principle.

But while Bartlett has already prospered (and possibly peaked), Dean has only now started to draw an audience. And if opponents succeed in “exposing” him as an un-Bartlett-like, consultant-driven creation, the governor will turn into the season’s latest flop. But at this point, history suggests that Dean’s opponents should assume he’ll be penciled into next year’s prime-time lineup.