BOSTON – Scott Ruffner, an antiwar activist who campaigned in Maine for Rep. Dennis Kucinich of Ohio, came to the Democratic National Convention an unhappy man – a delegate profoundly disappointed in the ticket his party was about to nominate.

After a week of hoopla and cheering for Sens. John F. Kerry and John Edwards, Ruffner left Boston feeling pretty much the same.

“My issues are never completely addressed,” said the real estate broker from Bangor. The convention, he said, was “a media spectacle that is trying to show a superficial unity.”

Still, Ruffner said with a sigh, he will work for Kerry even though he dismisses the nominee’s policies as “half a meal” – not bad on domestic issues but, to die-hard liberals, utterly misguided on foreign affairs.

Now that the convention has come to an end, many of America’s most liberal voters are finding that their dislike of President Bush exceeds their disappointment with Kerry. Their slogan: “Anybody but Bush.”

Yes, there is ample time between now and November for them to defect from the Democratic ranks. But if Kerry can keep their support stitched together, it could prove critical to the Democrat’s success in what promises to be a close election.

It matters because liberals are many of the foot soldiers who volunteer in a Democratic campaign, canvassing voters and getting them to the polls on election day. In a year when turnout is likely to be important, the enthusiasm of potential volunteers is a critical factor.

“Some people have made painful choices to support this ticket,” said activist and former California state Sen. Tom Hayden as the convention wound down. “The activist base of the antiwar movement sees the November election as a referendum on Iraq and on [President] Bush. … It’s separate from enthusiasm about John Kerry.”

For the Democratic Party to win a presidential election, its liberal and centrist wings must work together. While Bill Clinton managed that difficult fusion in 1992 and ’96, the party usually has had an easier time fracturing apart than pulling together. Consider Vice President Al Gore’s effort in 2000, when Green Party candidate Ralph Nader siphoned off disaffected liberals.

Second, and potentially more important, liberals have decided that Clinton was right: A centrist-liberal mix of fiscal discipline and cultural moderation is the party’s future.

“For all of [former Vermont Gov.] Howard Dean’s noise in the primaries, no one is saying we should do what he suggested, which was to concentrate on the [Democratic] base and ignore swing voters,” said Al From, chairman of the centrist Democratic Leadership Council. “This is a very different party from where it was when we started 20 years ago.”

A Kerry campaign aide said the moderate tone of the convention speeches – even those by most of the liberal champions – was no coincidence, because the event was designed to spotlight “Kerry the centrist, not Kerry the liberal.”

So the four-day event was a mixed bag for left-leaning delegates who attended and their counterparts who watched from home. Two speakers in particular stood out as impassioned ambassadors of the liberal world view and its continued place within the party ranks: the Rev. Al Sharpton of New York and Illinois Senate candidate Barack Obama.

“There’s not a liberal America and a conservative America,” Obama declared in the convention’s keynote address. “There’s not a black America and white America and Latino America and Asian America; there’s the United States of America. … There are patriots who opposed the war in Iraq and patriots who supported it. We are one people.”

Kucinich, Dean, the Rev. Jesse Jackson Sr. and Sen. Edward M. Kennedy of Massachusetts also addressed the delegates. But none of the liberal standard-bearers’ speeches was broadcast on network television.

Still, delegates watching from inside the hall and liberal voters tuning in on cable heard clear marching orders from their leaders this week.

Dean released his delegates early and urged them to vote for Kerry during the roll call of states in which the candidate is nominated. On Tuesday night, he told the convention, “We are all here to represent the Democratic wing of the Democratic Party.”

Kucinich, who stayed in the race until the very end, did not endorse Kerry until the week before the convention. He did not release his delegates to vote for Kerry until Monday; 37 of them voted for Kucinich anyway, denying Kerry a unanimous nomination.

But during progressive gatherings throughout the week, meetings with his delegates that resembled support groups and his convention speech Wednesday night, Kucinich declared his dedication for Kerry and urged his delegates to rally around the nominee.