Two years after President Obama's historic election, echoes of the grass-roots campaign that put him over the top in battleground states like Minnesota can still be heard on the University of Minnesota campus.

"Fired up?" shouts youth coordinator Mike Griffin, a staffer with Organizing for America, the street division of the Democratic National Committee (DNC), sometimes dubbed Obama's Army. "Ready to go!" comes the reply from a gaggle of volunteers with leaflets and voter registration cards at the ready for a throng of student revelers enjoying a bright, sunny Homecoming Day.

Without Obama at the top of the ticket, the remnants of his presidential campaign can hope to recapture only a sliver of the magic that brought 15 million new voters to the polls in 2008. In a year when some congressional Democrats have distanced themselves from the White House, Obama partisans also have to confront a history that tells them that participation by first-time voters falls precipitously in midterm elections.

"We have to work twice as hard," said Jeb Saelens, a student from Deer River, Minn., who heads an Organizing for America chapter at the University of Minnesota, where the president will appear Saturday at a get-out-the-vote rally. "But at least more people know what's going on. That's one thing Obama did."

Now what's at stake is not the White House, but a Democratic Congress that appears increasingly at risk of a Republican takeover. In a difficult year for Democrats, the ground game on display at the U is critical to the Democrats' chances of overcoming the GOP's apparent advantage in enthusiasm, fueled by a creaky economy and widespread Tea Party activism.

"Independent voters are flocking toward the GOP, and younger voters have become disenchanted former Obama supporters," said Tom Erickson, a spokesman for the National Republican Congressional Committee. "If this is the so-called army the Democrats are counting on to retain control of Congress and the governors' mansions, they're in for a world of hurt on election night."

In Minnesota, where any turnover in U.S. House seats would count as a major upset, Obama ground organizers say they have set up shop in every congressional district -- even if some are merely the home offices of the group's volunteers.

But the most concentrated energy is in the Twin Cities, home to two of the safest Democratic House seats in the nation, those that represent Minneapolis and St. Paul. Here, the focus is electing DFL nominee Mark Dayton for governor --a post Democrats haven't held in 20 years.

That's enough motivation for Kerry Felder, a nursing student whose participation in 2008 was limited to voting for Obama. This year, Felder began hosting phone banks and door-knocking expeditions for Dayton and other DFL candidates out of her home in north Minneapolis, an area the Obama campaign scoured for new voters two years ago.

"It's important to make change on a regular basis," said Felder, whose recent political activism springs from her work at a church food bank. "The country needs more people to get out and get active."

'Powerful tool'

New volunteers like Felder represent late but much-needed reinforcements to the ranks of Organizing for America, which grew from Obama's 2008 campaign organization and its vaunted 13 million-name e-mail list. Local organizers won't reveal how many names they have in Minnesota, other than to say that new names were added around the nation as the battles over the stimulus package and the health care overhaul dragged on.

"The important thing about the e-mail list is that it's sizable," said Graham Wilson, Organizing for America's Minnesota field coordinator. "It's a very powerful tool that we have."

If critics say Obama's Army appears to have faded since he was elected -- particularly compared to the noisy Tea Party rallies of the past year -- local partisans like Wilson say they haven't gone away.

"Our organizing wasn't focused on events a camera could see," Wilson said. "It was person-to-person contact."

Even by that measure, Obama's shock troops in Minnesota know they have a tougher slog than in 2008, when their pitch centered partly on a much-anticipated rendezvous with history. "What happened in 2008 was a generational thing," said DNC spokesman Frank Benenati. Comparisons to 2008, he said, simply aren't valid anymore.

Indeed, some recent polls show a drop-off in young people's engagement and interest in the 2010 midterm elections. That's a huge problem for Democrats, given Obama's overwhelming edge with so-called MTV voters in 2008. As things stand now, Republicans hope to pick up anywhere between 35 and 55 seats.

In the face of such grim predictions, the Democrats' best hope remains their database of "surge" voters from 2008, many of them young people and minorities.

One of those is Saelens, who voted for the first time in 2008. He says it was the spark for his involvement in politics. To the disappointment of his "ultraconservative" dad, Saelens changed his major from construction management to political science and became an Organizing for America leader at the U. His goal now? Recruit 1,000 campus volunteers before the Nov. 2 election.

At a DFL rally at Macalester College earlier this month, Saelens heard Vice President Biden ask party activists to "do for us what you did two years ago."

A campus rally with Obama on Saturday at Northrop Mall will undoubtedly help, as such rallies have in Wisconsin and other states where the president has drawn large crowds.

"Only Obama and his organization can reach those folks and make the case that this election is important to their lives," said Wellstone Action leader Jeff Blodgett, the Obama campaign's state director in 2008. "It's important to keep them involved in the off years. It's always hard."

The other piece of the puzzle is mobilizing the Democrats' traditional base of labor and minority voters for candidates from the governor on down. "We've got to find them and drag them in," said U.S. Rep. Keith Ellison, D-Minn., who has used his own campaign apparatus to boost turnout in the inner-city neighborhoods he represents. Ellison has a GOP opponent, Joel Demos, but appears to be in no serious danger of losing his seat.

Organizing for America has merged with the DFL's grassroots organizing effort to knock on doors and make calls in potentially competitive congressional districts. Between now and Election Day, the hot spots are southern Minnesota, where Democratic Rep. Tim Walz is a top GOP congressional target, and in the central part of the state, where Rep. Michele Bachmann is a top target for Democrats.

'Grass roots'

While the action on the ground is grass roots, the direction from above is not. GOP critics of the Democrats' nationwide campaign effort note that Organizing for America is run out of DNC offices in Washington.

"It drives me crazy," said Deanna Boss, a Republican candidate for the Minnesota House and an activist in the Tea Party movement, which has itself been criticized as the creation of powerful, moneyed interests. "They're not grass roots."

Organizers like Saelens say they don't see much of a ground game on the other side, at least not among young people. "I don't see Republicans talking to people or knocking on doors on campus," he said.

But as Saelens, Griffin and other Organizing for America workers canvassed their way across campus after the Gophers' homecoming game, the reception was not always a warm one. They braved taunts from a group of young men drinking in front of a fraternity on University Avenue, and faced a general lack of interest from the residents of another frat house next door.

The tally for the post-Homecoming afternoon: 23 new registered voters, and 25 new volunteer pledges.

"It's kind of battling uphill right now," said Seamus Dolan, an 18-year-old freshman volunteer from Bloomington who voted for the first time in the August primaries. "But that's how change starts."

Kevin Diaz is a correspondent in the Star Tribune Washington Bureau.