He began as a boutique candidate, the little-known former governor of Vermont with an unabashedly liberal message.
Now, having beaten all other Democrats in second-quarter presidential fundraising, Howard Dean is confirmed as a force to be reckoned with, the only Democrat with clear momentum as he pulls in his own base of supporters. The specters of Barry Goldwater (1964) and George McGovern (1972) - conservative Republican and liberal Democratic presidential candidates who lost their races spectacularly - loom on the horizon.
"Dean's running as good a campaign as can be imagined right now, because he's going directly to the voters," says independent pollster John Zogby. "That scares the Democratic establishment. But he doesn't need them now."
With six months to go before the first nominating votes are cast, analysts note, it's too soon to predict with any certainty who will win the Democratic nomination. Most voters haven't begun to pay serious attention to the 2004 race, and as events evolve - in Iraq, in the war on terrorism, in the US economy - Democrats' ideas about who best should challenge President Bush could change.
Polls show Governor Dean trailing in polls in the early nominating states, Iowa and New Hampshire. And even though he led in second-quarter fundraising with $7.5 million, he still trails Massachusetts Sen. John Kerry overall for money raised.
But Dean's insurgent candidacy - launched by his fierce opposition to the Iraq war - has garnered all the buzz, and has positioned him as a potential giant-slayer in the nomination battle.
There is still a lot of anger and bitterness among the Democratic electorate over the party's reaction to Iraq, beginning with the buildup to the war, when most major Democrats did not voice forceful opposition. That bitterness works against Democratic contenders like former House leader Dick Gephardt and Sen. Joe Lieberman.
"That's working to Dean's advantage," says John White, a political scientist at Catholic University. "The question is ... can he sustain those advantages against an onslaught on his persona? Does he have the temperament to be president? What about his lack of foreign-policy experience? Can he win? Kerry is going to mount an assault on all those characteristics."
That Dean now faces a new level of scrutiny is without question. Already, comparisons with Sen. John McCain (R) of Arizona - the 2000 election's maverick antiestablishment hero - end when the issue of press relations comes up. Dean is notably prickly with reporters who question him hard, in contrast with McCain's easy rapport
With Dean supporters, combativeness with journalists can work to his advantage. When the Vermonter turned in a rough performance on "Meet the Press" last month, facing an equally combative Tim Russert, campaign donations poured in. Dean has also made extremely effective use of the Internet, both in organizing and in fundraising, enhancing his ability to bypass the filter of the traditional press.
But can Dean keep expanding his base? And will his constituency of white, Internet-savvy professionals stick with him to the end of the nominating process? Every step, Dean will have to fight the idea that as a hard-core liberal, he is unelectable.
Some analysts say "electability" doesn't matter to many Democratic voters.
"The calculation for liberals is this: Right now it looks as if Bush is a heavy favorite to win reelection, so if you're going to lose anyway, lose with somebody you like," says John Pitney, a political scientist at Claremont McKenna College in California. "If something happens, such as another recession or a scandal, then any of the Democrats could win, including Howard Dean."
One issue that could be tricky for Dean is his support for same-sex "civil unions," which are legal in Vermont. The Supreme Court ruling last week legalizing gay sexual practices has spurred debate on the possibility of gay marriage, and will put Democratic candidates on the spot. Public opinion in recent years has grown more hospitable to equal rights for homosexuals, but in two early-contest states - Iowa and South Carolina (but not New Hampshire) - social conservatism has the edge.