African-Americans had some impact in the 2004 Democratic presidential primaries, making up nearly half of the party's voters in South Carolina and Georgia, a third or more in Virginia and Louisiana, and a fifth or more in New York, Texas, and Tennessee.
But despite those sizable numbers, only a small fraction of the black residents of those and other states went to the polls - 11 percent in South Carolina, 18 percent in Georgia, and just 9 percent in Louisiana, according to census figures and state election results.
The wide gap reflected in those two sets of figures - between the number of African-Americans who voted in the 2004 primaries and the number who did not - is where Senator Barack Obama sees a huge opening as many states with large black populations head to the polls over the next month to select a Democratic nominee.
Obama, the most viable black presidential contender in history, has largely not made race an issue in the campaign, expressing pride in his biracial background but emphasizing commonalities across color, class, geography, and political persuasion. His ability to bridge the black and white worlds has helped make him a leading contender for the Democratic nomination despite his recent arrival to national politics.
But beneath Obama's unifying message lies a shrewd political calculation: He and his campaign, sensing a largely untapped reservoir of potential support, are making concerted efforts to reach out to African-American voters. Those efforts are intensifying now that Iowa and New Hampshire have voted and larger, more racially diverse states are poised to determine the course of the primary contest - starting with South Carolina this Saturday.
Polls suggest the work is paying off, but Obama still faces a central question: Much like Senator Hillary Clinton, who won New Hampshire by drawing women to the polls in unprecedented numbers, can Obama increase the African-American turnout enough to win delegate-rich states and march to the nomination?
"Certainly on paper and organizationally that was their goal," said Carey Crantford, a pollster in Columbia, S.C., not affiliated with any campaign. "Can they perform? That's the question now."
Obama's push for black voters, who overwhelmingly tend to vote Democratic, carries implications not only for the primaries, in which he is battling Clinton and John Edwards for African-American support, but potentially for the general election, too. Pressed by a New Hampshire voter last summer about his electability, Obama boasted that he could "actually redraw the political map."
"I guarantee you African-American turnout, if I'm the nominee, goes up 30 percent around the country - minimum, " Obama was quoted as saying by the Associated Press, suggesting that Mississippi, Georgia, and other states would suddenly be in play for Democrats.
Analysts called that prediction an exaggeration, but some say Obama's larger point about his potential to motivate and mobilize black voters was sound.
"It's absolutely reasonable to say," said John Della Volpe, the polling director at Harvard University's Institute of Politics, pointing out that similar predictions made by Obama's campaign about turning out new voters came true in Iowa and New Hampshire.
To be sure, Clinton and Obama draw heavily from each other's constituencies. Obama won Iowa by beating Clinton among women; Clinton enjoys strong support among African-Americans and is using prominent black leaders to pitch her message, including former Los Angeles Lakers star Magic Johnson, who just made a 60-second ad to run on South Carolina radio.
"Obama isn't the only candidate pursuing a large black turnout," said Donna Brazile, who ran Al Gore's campaign in 2000 and is neutral this year. "Both candidates are putting [in] a lot of energy, a lot of resources, a lot of time, and a lot of surrogates."
But polls, particularly since Obama's win in the Iowa caucuses, indicate that black voters are breaking increasingly for the Illinois senator, a trend that bodes well for his candidacy if his campaign can get African-Americans to the ballot boxes.
In South Carolina, Obama has a 23- to 44-point lead over Clinton among African-Americans, according to polls conducted last week. In the fall, Obama and Clinton were nearly even.
In New Jersey, which votes Feb. 5, blacks now favor Obama over Clinton 48 percent to 26 percent, according to a new poll by Monmouth University. In October, Obama led by just 3 percentage points. And in Alabama, another Feb. 5 state where Clinton and Obama have jostled for the lead among African-Americans, a new Capital Survey Research Center poll has Obama up 54 percent to 20 percent.
Clinton fared poorly among black voters in Tuesday's Michigan primary. Although she was the only leading Democrat who kept her name on the ballot after the Democratic Party stripped the state of its delegates, exit polls show that African-Americans who voted chose "uncommitted" over Clinton 68 percent to 30 percent.
The surge in black support that Obama is enjoying, analysts and supporters say, is due in large part to his win in Iowa and close second-place finish in New Hampshire, which they say sent a message to black voters nationwide that whites are willing to vote for him.
"The electability issue was weighing him down," said US Representative Artur Davis of Alabama, an early Obama supporter. "After Iowa, there was a significant, dramatic movement of black voters because they now see that Barack Obama can capture significant support in the white community."
For Obama to win the nomination, of course, he must also attract enough support from white voters, who are still likely to make up the bulk of the Democratic electorate across the 30 states that vote in the next four weeks. Polls suggest that Clinton has a wide lead over Obama among whites in some early states - 46 percent to 23 percent in New Jersey, according to the Monmouth survey, and 44 percent to 20 percent in South Carolina, according to a Rasmussen poll last week.
But as Obama works to close those gaps, he is acutely aware of how powerful a record turnout of black voters could be, and so his campaign is targeting black audiences in myriad ways.
This morning, Obama is scheduled to speak at Dr. Martin Luther King's former church, Ebenezer Baptist Church in Atlanta. Several well-known black actresses, including Jasmine Guy and Alfre Woodard, campaigned for him in South Carolina earlier this month. And Obama's wife, Michelle, last week made a "homecoming" trip to Georgetown, S.C., where her grandfather was from. She spoke Monday to a "packed house" at her grandfather's old church, according to the campaign.
"For all their vaunted political skills, I think the Clintons still think they're facing Newt Gingrich and the Republicans, and they're not," said David Bositis, a specialist on black voting patterns at the Joint Center for Political and Economic Studies, a nonprofit organization in Washington.
What may have the greatest impact, though, is the Obama campaign's more mundane work of identifying, registering, and mobilizing new African-American voters. It is work Obama knows well.
After law school in the early 1990s, he returned to Chicago to run a voter registration project, adding 150,000 African-Americans to the city's rolls. That push benefited another young presidential aspirant making a run at the White House: an Arkansas governor named Bill Clinton.
Globe correspondent Amy Farnsworth contributed to this report. Scott Helman can be reached at shelman@globe.com.
