They captured the White House under a mantra of "change" and scored big House and Senate gains promising a "new direction."
Now Democrats have to figure out how to fulfill those lofty promises without alienating the very people who handed them the keys to the government for the first time in more than a decade.
Barack Obama and dozens of Democratic congressional candidates won Tuesday by resurrecting the party's brand in the South, Midwest and West, reaching deep into GOP territory, much of it conservative ground. They activated new voters, especially the young and minorities.
The result was a stronger hand in Congress and the election of a charismatic new national leader. But instead of claiming a broad mandate for their most cherished priorities, Democrats are sounding notes of caution rooted in painful lessons of the past.
They won't overreach, they promise, even as the liberal activists who form their base clamor for fast, sweeping changes.
"The country must be governed from the middle," said House Speaker Nancy Pelosi, D-Calif., who has spent much of the last two years working to quell intramural fights between liberals and conservatives on everything from ending the Iraq war to curbing the deficit. "You have to bring people together to reach consensus on solutions that are sustainable and acceptable to the American people."
She also acknowledged, however, that Obama faces "more expectations than any president I can ever remember in my life time."
'Old Virginny is dead'
So does his party.
New footholds in regions long considered off-limits to Democrats yielded historic breakthroughs they will have to work hard to retain.
Virginia Gov. Tim Kaine, who helped guide Obama to victory in the former Confederate capital, declared Wednesday that "Old Virginny is dead." He said Obama's triumph in Virginia — the first for a Democrat seeking the presidency in 44 years — was the apex of everything he had worked for since law school. Even North Carolina, which has been reliably Republican in presidential politics since 1980, was still too close to call Wednesday.
In the House, Democrats took control of every seat in New England, the entire New York City delegation and two seats in New Mexico held by Republicans for decades. They made important gains in every region, including in conservative areas of Virginia, Alabama and North Carolina. In the Senate, too, Democrats claimed seats in the South, West and New England.
"We have an historic opportunity to build a long-term governing and political majority," said Al From, head of the centrist Democratic Leadership Council, a launching pad for Bill Clinton.
Big challenges ahead
Democrats view Clinton's first two years as a cautionary tale. They got off to a troubled start with the derailing, at the hands of conservative Democrats, of his campaign promise to lift the ban on gays in the military. The collapse of his far-reaching health care plan added to the problems, and intramural spats derailed enough other Democratic priorities to help usher in the so-called Republican revolution that cost the party control of Congress in 1994.
From said Tuesday's results meant Democrats' first chance in recent memory to build "a progressive, centrist" coalition.
That will sometimes mean doing things that have been anathema to liberals — such as overhauling education, expanding international trade and cutting spending — and at least temporarily leaving aside others, like organized labor's long-held hope of winning legislation to allow them to unionize workplaces without secret ballot elections.
"When you're out of office for a very long time, there are a lot of pent-up demands. I hope and I believe that President Obama will keep the focus on really tackling the big challenges," From said.
Liberals were sounding a different note, however.
"This is not simply a change election; it's a sea change election," Robert Borosage, co-director of the Campaign for America's Future, a liberal activist group, told reporters in a conference call Wednesday. He rejected the notion that Democrats should check their agenda to fit a shifting base.
"If Obama is to be a successful president, he has no choice but to be a transformative one, pushing for bold changes big enough to deal with the scale of our problems," Borosage said.
No overnight miracles
Still there are practical limits to what Democrats can — and should — do, party veterans insist. Their agenda will be crimped by a lingering financial crisis that's further straining an already strapped federal budget. And it will have to be checked by an unrelenting calendar: In less than two years, all of them, including a new crop of freshman from swing districts, will have to answer to voters for their achievements and failures.
"No one should expect miracles to occur overnight, and it is very important that the members from conservative districts and moderate districts, and conservative and moderate states, be listened to as the agenda is being put together. Otherwise, the Democratic party runs the risk of losing many of these seats in the next election," said former Democratic Rep. Martin Frost of Texas, who headed the party campaign committee when the GOP saw its 1994 revolution fizzle after steering Congress sharply to the right.
Indeed, Rep. Tom Cole, R-Okla., head of his party's campaign committee, was crowing even before some polls had closed Tuesday night about his party's chance to make a comeback in 2010 based on Democratic overreaching.
"They're going to drag a lot of their more moderate and conservative colleagues into dangerous territory in the next two years," Cole said. "We'll pick up seats" in 2010.
Leading from the center
Republican National Committee Chairman Mike Duncan said Obama will be successful if he can resist pressure from liberals.
"I offer the advice to not lurch to the left," Duncan said at a luncheon Wednesday at the National Press Club. "He leads a center-left party, but he must govern a center-right party."
Howard Dean, the Democratic Party chairman, said his strategy of aggressively competing in every area of the nation paid off for Democrats who now have to answer to a new generation of voters uninterested in partisan sniping.
"You can't be a national party if you're willing to write off entire parts of the country," Dean said.
"I think it's a mandate that the political class in this country has an obligation to young people in this country to stop fighting over stuff that might have been (important) 25 years ago but it isn't anymore."