WASHINGTON — Perhaps the last time America really focused on Howard Dean, he was wearing a blue shirt with the sleeves rolled up, holding a microphone and pumping his fist, and hollering after the 2004 Iowa caucuses.

"It is remarkable the degree to which Dean's 2004 scream remains his defining political event," said political analyst Larry Sabato. Indeed, the speech is still the most viewed video of Dean on YouTube.

On Saturday, though, the former Democratic presidential candidate and Vermont governor faces one of the most important moments in his three and a half years as chairman of the Democratic National Committee. The Rules and Bylaws Committee will meet to decide whether to seat delegations from Florida and Michigan at the Democratic National Convention. The two states had been forbidden from sending delegates to Denver in August because they violated party rules to move their primaries ahead in the campaign season.

The committee has members fiercely loyal to both remaining Democratic candidates — Illinois Sen. Barack Obama and New York Sen. Hillary Clinton. The outcome is certainly crucial to Clinton's dwindling chances at the nomination. Dean must help broker a deal that will satisfy supporters of both candidates enough to ensure that a united party comes out of the convention ready to defeat Arizona Sen. John McCain, the presumptive Republican candidate.

"If Democrats lose, Dean won't be the only one screaming" come November, said Sabato, director of the University of Virginia's Center for Politics and author of "A More Perfect Constitution."

Despite a few outspoken gaffes — declaring "I hate the Republicans and everything they stand for," for instance, and proclaiming that Republicans "have never made an honest living in their lives" — Dean has gotten generally high marks as head of the party. After all, he was in charge when the Democrats won control of Congress in 2006.

"I think he's been a terrific party chairman and 2006 was a reflection of his leadership," said Elaine Komarck, a Democratic super-delegate and member of the Rules and Bylaws Committee. She would not discuss Dean's involvement in Saturday's meeting.

"I will not talk about committee negotiations," explained Komarck, who teaches at Harvard's Kennedy School of Government.

But critics of Dean question whether the physician-turned-politician is suited for sensitive negotiations. He has been known more for bluster than for bargaining.

"He's very presumptuous. He knows everything. That's part of the doctor style — 'I'll tell you what you need to do. If you do it, you'll get well. If you don't, you'll die,'" said Garrison Nelson, a political science professor at the University of Vermont.

"He's the strangest guy to be in public life I've ever met. He doesn't like people," said Nelson, a long-time critic of his state's former governor. "Howard is not a man of subtlety."

Dean, 58, was characteristically blunt in pointing out that the situation was caused by Florida and Michigan breaking the rules.

"From the beginning, we made clear that any state that moved its primary up would lose its delegates. Back in August of 2006, the full membership of the Democratic National Committee, including representatives from Florida and Michigan, voted on the rules guiding the 2008 nominating contest," he said.

"If the DNC's Rules and Bylaws Committee had not enforced its rules, it's easy to imagine state after state leapfrogging ahead in an effort to be first, knowing full well there would be no consequences for their actions. The DNC was left with little choice but to stick to the pre-determined rules or leave the calendar vulnerable to chaos."

The long primary season and late focus on super-delegates and delegate disputes should not have surprised party leaders, said Tad Devine, a Democratic political consultant not involved in either the Obama or Clinton campaigns.

"I think it was very foreseeable" given the proportional division of delegates in primaries and two strong campaigns, said Devine. "But I don't fault him for the foreseeability of this. I think Gov. Dean overall has done a good job. The big test for somebody in his situation is to be fair."

"I think he's tried to be fair," said Devine.

Throughout the campaign season, Dean has been largely left in the shadows as history is being made with an African-American presidential candidate battling a female contender.

"I may not know which 'first' it will be but I'm confident that America will elect a Democratic 'first' as its next president," said Dean. "I fully hope and expect that both Barack Obama and Hillary Clinton will help keep our party united in the general election and ensure that we win in November, no matter who wins the nomination."

He declined to say what has been discussed about the negotiations over the Florida and Michigan delegations or how he is trying to unite the competing candidates.

? "I'm personally engaged in this process and talk to both campaigns and Democratic leaders across the party frequently but I'm not going to discuss private conversations publicly," he replied to e-mailed questions.

As DNC chairman, Dean began a "50-state strategy" to organize the party and try to win elections at every level in every state — even those states that have voted overwhelmingly for Republicans in recent years.

"He's made it possible for Democrats to win in deep "Red States," said Nelson. "He has helped deepen the base of the party."

The results came when Democratic candidates picked up vacant House seats that had long held by Republicans in Mississippi and Louisiana.

"We're truly a national party again and we're ready to win in November," said Dean. During the primary season, "Democratic turnout has been nearly double Republican turnout."

"The challenge will be to keep the party unified and that's my primary focus," he said.

"Dean will ultimately be judged by the '08 results," said Sabato. "If Democrats win, he'll be saluted by most. If the party blows the presidential election under nearly ideal conditions, Dean will be severely criticized, and the Michigan-Florida situation will be at the center of his critique."

"Dean's greatest contribution has been in trying to expand Democratic efforts in Republican Red territory," said Sabato. "His greatest weakness has been in fund-raising."

At the end of April, the DNC had collected $22.8 million in 2008 and had $4.4 million left to spend. That compared to $57.6 million raised by the Republican National Committee, which had $40.6 million left to spend. The DNC faced a donor base already drained by the record amounts raised by the Obama and Clinton campaigns.