“People are seeing other constituencies getting their issues addressed and are wondering why is it that African-Americans haven’t been able to get their issues on the national agenda,” said Fredrick Harris, the director of Columbia University’s Institute for Research in African-American Studies and the author of the book “The Price of the Ticket: Barack Obama and the Rise and Decline of Black Politics.” “Black unemployment is high. People feel like there needs to be targeted efforts.”

Sensing an opportunity, presumptive Republican presidential nominee Mitt Romney will address the NAACP on Wednesday.

“Unlike President Obama, (Romney) will not take any vote for granted,” said Tara Wall, an African-American adviser for Romney’s campaign. “Every percentage point that we chip away from President Obama counts. . . . While Gov. Romney acknowledges that he will not get a majority of support from black voters, he also recognizes that President Obama can no longer count on the margins he once enjoyed. We aim to seize on those opportunities.”

The fate of the electoral votes in Ohio, Nevada, Florida, North Carolina, Virginia and perhaps other states could hinge on the result.

"African-Americans are still plenty excited about Obama," said Larry Sabato, the director of the Center for Politics at the University of Virginia. "I expect turnout to be pretty strong."

Obama campaign officials say they’re not taking African-Americans – or any other voters – for granted. Aides recently called African-American voters “the bedrock of our support.”

The campaign insists that African-American turnout will match 2008, when two out of five new voters surging to the polls were African-American. Their voting rate was up 4 percentage points from 2004, while the rate for non-Hispanic whites dropped about 1 percentage point.

That made a difference in swing states, and it could again. The outlook for African-American votes:

– Nevada. 2008 result: Obama 94, McCain 5. African-American share of vote: 10 percent. Obama could benefit from the campaign of state Senate Majority Leader Steven Horsford, an African-American who’s running for Congress. "You don’t have the enthusiasm you had in 2008, but if there are candidates close to home who bring people out, it could help the top of the ticket," said David Damore, an associate professor of political science at University of Nevada, Las Vegas.

– North Carolina. 2008 result: Obama 95, McCain 5. Black share: 23 percent. Democrats in the state are in disarray. Blair Kelley, an associate professor of history at North Carolina State University, thought that could be a motivator to turn out Democrats. "I wouldn’t assume being back on your heels means you do less. It means you do more," she said.

– Ohio. 2008 result: Obama 97, McCain 2. Black share: 11 percent. "A series of issues have played well in the African-American community. The (2009 economic) stimulus helped a community really hit hard by the recession, and the promise of near-universal health care is particularly attractive," said Paul Beck, a professor of political science, sociology and communication at Ohio State University.

– Virginia. 2008: Obama 92, McCain 8. Black share: 20 percent. "African-Americans are still excited about the president, and you’re going to stay within a point or two" of turnout last time, Sabato said. – Florida. 2008 results: Obama 96, McCain 4. Black share of vote: 13 percent. As in many states, "it’s unclear if the turnout will match 2008," said Merle Black, a Southern history expert at Emory University in Atlanta. Should Romney put Sen. Marco Rubio, R-Fla., on the ticket, Florida probably becomes less important for Obama.

Obama campaign officials say they’re taking no chances. They’ve launched grass-roots programs targeting African-American barbershops and beauty salons, businesses and even nightclubs.

The White House dispatched first lady Michelle Obama to the African Methodist Episcopal Church convention last week in Nashville, Tenn., where she warned attendees of the dangers of sitting on the sidelines this election year.

“Let’s be very clear: While we’re tuning out and staying home, other folks are tuning in,” she said.