After staying on the sidelines in the first year of the campaign, race and to a lesser extent gender have burst into the forefront of the Democratic presidential contest, thrusting Senators Barack Obama and Hillary Rodham Clinton into the middle of a sharp-edged social and political debate that transcends their candidacies.
In a tense day of exchanges by the candidates and their supporters, Mrs. Clinton suggested on Sunday that Mr. Obama’s campaign, in an effort to inject race into the contest, distorted remarks she had made about the Rev. Dr. Martin Luther King Jr.
Mr. Obama tartly dismissed Mrs. Clinton’s suggestion, adding that “the notion that somehow this is our doing is ludicrous.”
Mr. Obama’s campaign then attacked Mrs. Clinton for failing to repudiate one of her top black supporters for “engaging in the politics of destruction” with an apparent reference to Mr. Obama’s acknowledged drug use in the past. And throughout the day, supporters of Mrs. Clinton and of Mr. Obama each accused the other of injecting race in search of political gain.
The exchanges created apprehension among many of their supporters who viewed this moment — if perhaps inevitable, given the nature of the contest — as divisive for Democrats. At the same time, it offered a portrait of a party struggling through entirely unfamiliar terrain that has been brought into relief by Mr. Obama’s victory in Iowa and Mrs. Clinton’s in New Hampshire.
Two factors have helped create the atmosphere in which race and gender are coming to play a more prominent role. The first is that Democrats now increasingly view both Mr. Obama and Mrs. Clinton as credible and electable candidates, given their victories.
In addition, Mrs. Clinton and Mr. Obama are now moving into a series of contests, particularly in South Carolina but also in California, where black voters could play a pivotal role.
Indeed, both Mrs. Clinton and Mr. Obama spoke from the pulpits of black churches on Sunday, Mr. Obama in Las Vegas and Mrs. Clinton in South Carolina.
The candidates and their campaigns have not been innocent bystanders to all this. In fact, since her loss in Iowa, Mrs. Clinton has, subtly but unmistakably, pushed gender, engaging in a series of events intended to present her in softer ways. Many Democrats believe that Mrs. Clinton won New Hampshire after a decisive swing of women into her camp, particularly after a debate on the Saturday night before the primary in which John Edwards and Mr. Obama joined forces in criticizing her.
“I never thought we would see the day when an African-American and a woman were competing for the presidency of the United States,” she told black parishioners at a Presbyterian church in Columbia, S.C. “Many of you in this sanctuary were born before African-Americans could vote. So this is not a piece of history that is happening to someone else; this is happening to us.”
Mr. Obama, reflecting the different way he has talked about race during his own campaigns, took pains in speaking at a church service here on Sunday to avoid portraying his election as historic because of the possibility of putting an African-American in the White House.
“We’re on the brink or cusp of doing something important; we can make history,” Mr. Obama said, speaking to a few hundred worshipers at the Pentecostal Temple Church of God. “I know everybody is focused on racial history. That’s not what I’m talking about. We can make history by being, the first time in a very long time, a grass-roots movement of people of all colors.”
Mrs. Clinton said Sunday, in an interview on the NBC program “Meet the Press,” that she was hopeful race and gender would not be an issue in this contest.
Still, supporters of Mr. Obama said in interviews Sunday that they were concerned Mrs. Clinton and her allies might be deliberately raising the issue of race at the very time that Mr. Obama had shown signs of taking off.
“I don’t want to believe that, but I’ve got to tell you I’m wondering,” said Representative Elijah E. Cummings, a Maryland Democrat who is black and an Obama supporter. “I don’t want to believe it is true.”
Mrs. Clinton and her supporters denied that. Geraldine A. Ferraro, who was the Democratic candidate for vice president in 1984, said she thought Mr. Obama and his campaign were fanning the issue to draw black voters away from Mrs. Clinton before the primary in South Carolina, where about 50 percent of the electorate is expected to be black.
“As soon anybody from the Clinton campaign opens their mouth in a way that could make it seem as if they were talking about race, it will be distorted,” Mrs. Ferraro said. “The spin will be put on it that they are talking about race. The Obama campaign is appealing to their base and their base is the African-American community. What they are trying to do is move voters from Clinton by distorting things. What have they got to lose?”
In a sign of how the issue was churning the waters, Mr. Edwards, also speaking at a church in South Carolina, expressed pride in Mr. Obama while criticizing Mrs. Clinton for what some have seen as her suggesting that President Lyndon B. Johnson deserved more credit than Dr. King for the Civil Rights Act of 1964.
“As someone who grew up in the segregated South, I feel an enormous amount of pride when I see the success that Senator Barack Obama is having in this campaign,” said Mr. Edwards, who grew up in North Carolina. He added: “I was troubled recently to see a suggestion that real change came not through the Rev. Martin Luther King, but through a Washington politician. I fundamentally disagree with that.”
Mr. Obama spoke in general terms Sunday about the attacks on his candidacy on a day when Mrs. Clinton specifically challenged his record on opposing the Iraq war.
“I think they have decided to run a relentlessly negative campaign, and I don’t think anybody who’s watching would deny that,” he said. “I gather that she’s determined that instead of trying to sell herself on why she would be the best president, she’s trying to convince folks that I wouldn’t be a good one.”
Aides to both Mrs. Clinton and Mr. Obama expressed squeamishness at the direction the conversation was heading. And publicly, the campaigns spent much of the day shadow-boxing on an issue that advisers to both of them described as volatile. The issue broke through when Robert L. Johnson, the founder of Black Entertainment Television, who appeared at a rally with Mrs. Clinton in Columbia, S.C., seemed to allude to Mr. Obama’s use of cocaine as a young man.
“To me, as an African-American, I am frankly insulted that the Obama campaign would imply that we are so stupid that we would think Hillary and Bill Clinton, who have been deeply and emotionally involved in black issues since Barack Obama was doing something in the neighborhood — and I won’t say what he was doing, but he said it in the book — when they have been involved,” Mr. Johnson said.
Mr. Johnson later issued a statement saying he was referring to Mr. Obama’s work as a labor organizer in Chicago, which he described in his book “Dreams From My Father.”
Asked about Mr. Johnson’s statement, Mr. Obama said, “What’s there to respond to?”
“I’m not going to spend all my time running down the other candidates, which seems to be what Senator Clinton has been obsessed with for the last month,” he said.
Reporting was contributed by Julie Bosman in Myrtle Beach, S.C.; Patrick Healy in New York; Katharine Q. Seelye in Columbia, S.C.; and Jeff Zeleny in Las Vegas.