BOWIE, Md. | On the corner of Collington Road and Route 301 in this close-in Maryland suburb of Washington, a bright blue poster screams the Democratic Party's wishful thinking at passing cars: "We've got your back, President Obama."
The poster, not quite big enough to qualify as a billboard, reflects an unspoken bargain between Mr. Obama, the nation's first black president, and black voters: He asks, they deliver.
Last week, Mr. Obama asked.
Polls indicate many minority voters are discouraged and won't turn out Nov. 2 as they did for Mr. Obama two years ago, yet a solid showing among blacks could still swing several House, Senate and gubernatorial races, according to some analysts.
Black voters are "strategically located" to affect as many as 20 House races, mostly in Southern states, explained David Bositis, a senior researcher at the Joint Center for Political and Economic Studies, who has analyzed the black electorate for more than two decades. They also could sway more than a dozen Senate and gubernatorial races, Mr. Bositis said.
"It's not something where the Democrats and the candidates are going to be out there yelling, 'We want the black vote,'" he said. "They're going to work through the black churches, the black media."
The 20 House races where black turnout could determine the winner, according to Mr. Bositis' analysis, are in 14 states: Alabama, Arkansas, Delaware, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, Ohio, South Carolina, Tennessee, Texas and Virginia.
Mr. Bositis said this election could echo midterm elections in 1986, when significant black turnout helped Democrats gain House seats and take control of the Senate, and again in 1998, when Democrats picked up governorships in Alabama, South Carolina and Georgia.
Both of those elections followed events that resonated with black voters: Jesse Jackson's historic presidential campaign in 1984 and the GOP effort in 1998 to impeach President Clinton.
Back then, congressional Republicans "were attacking Bill Clinton just like they are attacking Obama right now," Mr. Bositis notes. "And Obama is more popular with African-Americans than Clinton was."
While many Democrats are distancing themselves from the president on the campaign trail in conservative districts, the party's approach with black voters is to make the election about the president and his agenda.
University of Chicago political scientist Cathy J. Cohen said Democrats hope that by framing the election around the attacks on Mr. Obama and racial polarization arising out of the "tea party" movement, "black voters will mobilize in particular districts so they can tip the balance." Tea party leaders sharply dispute any suggestion that their movement is based on race, saying their primary issues are government spending and the deficit.
"I still think that black people will come out and vote for what they think is the president's agenda, which is to vote Democratic," said Ms. Cohen, author of a new book on black youth and politics. "A solid black turnout will be fine in some seats. But they need the excitement of 2008."
To that end, the Democratic National Committee is spending $2 million on ad buys in African-American media, far more than it spent in previous midterm elections. The president himself stopped by a White House briefing earlier this week for black bloggers and journalists from black-oriented media. He has scheduled a meeting at the White House with the Trotter Group, a group of black newspaper columnists.
The "got your back" posters stand at several major intersections in Prince George's County - home to the largest black community in the state and also the home of Republican National Committee Chairman Michael S. Steele.
At last week's rally in Bowie, Mr. Obama told the crowd, "What the other side is counting on is that this time around, you're going to stay home. They figure Obama's not on the ballot, you're not going to come out and vote. Well, Maryland, you have got to prove them wrong."
Whether that message is getting through to enough black Democratic voters is an open question.
Joyce Walker, 55, of Bowie said she feels her fellow Democrats "might take a big hit" next month because many core voters are not fully engaged in races not involving Mr. Obama.
"Most people, they're not enthusiastic about the governor's election. They're mostly enthusiastic about the president," she said.