The Democrats ''are a party of the future, while Republicans are the party of the past," Dean said.
''We need to be proud to be Democrats," said Dean, recalling the kind of exuberant appearances he made during 2003 when he came close to winning the Democratic presidential nomination before the effort fell apart in Iowa.
''We have to never be afraid to say what we believe," Dean said, as the crowd roared its approval. ''Above all, we need to stand up for a different vision."
On the steps of the restaurant-brewery where the event was held, he urged supporters to look behind them at the brightly lighted, white dome of the Capitol.
''After 2006, we will make major strides in regaining that building, and in 2008 we're going to have it," Dean said. ''In 2008, there will be a Democrat walking down Pennsylvania Avenue to the other end."
Supporter Rebecca Cague watched Dean with a wistful smile.
''I feel like he is what we need to revive the party," she said. ''He's not afraid to speak his mind; and when he does, he speaks for us."
Dean promised to work closely with top congressional leaders such as Senate Democratic leader Harry Reid and House Democratic leader Nancy Pelosi and with Democratic officials at the national, state, and local level.
As Dean worked up the crowd, one of his supporters shouted: ''Give 'em hell, Howard!"
''I'm trying to be restrained in my new role," Dean said with a mischievous grin. ''I may be looking for a three-piece suit."
He paused and then burst out laughing. ''Fat chance!"
Dean is set to be elected party chairman on Saturday, but was careful to assume nothing after his late collapse in the presidential race, starting phrases with ''If I am elected chairman of the Democratic Party . . ."
All other candidates for chairman have dropped out of the race.
And Democrats have been falling in line behind Dean's chairmanship, hoping to gain from his energy and network of supporters.