Senator Clinton’s comment stressing the importance of President Johnson at the expense of the role of Martin Luther King Jr. may come back to haunt her in the battle to attract African American voters, who make up half of the Democratic electorate in the upcoming South Carolina primary.

The situation underscores the perils for Mrs. Clinton as she confronts a challenge for the Democratic presidential nomination from Senator Obama. Her attempts to criticize Mr. Obama risk backfiring and alienating black voters, an important Democratic constituency.

A New York Times editorial yesterday highlighted the problem for Mrs. Clinton — rather than congratulating her for her victory in the New Hampshire primary, it cautioned that Mrs. Clinton “came perilously close to injecting racial tension into what should have been — and still should be — an uplifting contest between the first major woman candidate and the first major African-American candidate.” The Times editorial went on to say of Mrs. Clinton’s comment, “It was hard to escape the distasteful implication that a black man needed the help of a white man to effect change.”

The Obama camp and civil rights leaders independent of the political campaigns yesterday seized on Mrs. Clinton’s statement, “Dr. King’s dream began to be realized when President Lyndon Johnson passed the Civil Rights Act of 1964…It took a president to get it done.”

Assemblyman Karim Camara, a Democrat who represents Crown Heights, Brooklyn, and who is supporting Mr. Obama, said, “I got calls from constituents and from other elected officials and from pastors who were surprised.” Mr. Camara, who is the executive pastor of the First Baptist Church of Crown Heights and said he plans to trek to South Carolina along with a delegation of other New Yorkers, said Mrs. Clinton’s words could affect the outcome of the campaign, particularly in the religious community. King, after all, was not only a black leader but an ordained minister.

“I believe churches are very sensitive to the language we use,” Mr. Camara said. “This can have a tremendous impact in increasing their level of churches in going out and supporting Senator Obama.”

The flap resonated yesterday in a day that saw Mr. Obama receive the endorsement of the mayor of Atlanta, Shirley Franklin. Also yesterday, a co-chairman of Mr. Obama’s campaign, Rep. Jesse Jackson Jr. of Illinois, questioned Mrs. Clinton for welling up during a political appearance in New Hampshire but not after Hurricane Katrina.

Still, attitudes of blacks toward Mr. Obama and Mrs. Clinton often turn on generational fault lines, with younger voters curious about the 46-year-old senator from Illinois and older voters wary of him and comfortable with the more seasoned senator from New York, experts and community leaders told the Sun.

“I thought her comments were not only out of line but it seemed to me to be desperate and a misreading of history,” the executive director of the New York Civil Rights Coalition, Michael Meyers, said. “To say that President Lyndon Johnson was the one who did that when we know he could not do that without President Kennedy’s assassination and death and the change in the national mood on civil rights is astonishingly ignorant.” He added that the statement was also “ignorant of the participation of everyday people, including Dr. King.”

The debate could get additional mileage with the approach of Martin Luther King Day, a federal holiday that this year is observed Monday, January 21. A national spokesman for the Congress of Racial Equality, Niger Innis, attributed Mrs. Clinton’s statement to her determination to block Mr. Obama’s rise and save the nomination for herself. “It seems to me Hillary was trying anything to stop the momentum that seemed unstoppable until yesterday at 10 o’clock,” Mr. Innis said. He contended that Mrs. Clinton’s victory Tuesday night would block a groundswell of support among African American voters for Mr. Obama. “If Barack Obama had won and the possibility of a black candidate attaining a major political party’s nomination is within reach, you could be sure that blacks would come out for him in major numbers in South Carolina and the rest of the country.”

A Rasmussen Poll Monday reported that Mr. Obama had the support of 58% of black voters. Many African American politicians, however, such as Rep. John Lewis of Georgia and Rep. Charles Rangel of New York, have opted to endorse Mrs. Clinton.

“I think older African American are concerned about his lack of experience and feel affection for the Clintons,” said a professor at George Mason University and the author of “Republicans and the Black Vote,” Michael Fauntleroy. He said “I think it’s an overstatement of his achievements to compare him with King. Barack Obama has never led anything and never made any societal change.”

Given that there are some African Americans who feel some distance from Mr. Obama given his unique background as the son of a Kenyan and a Kansan, his wife, Michelle, may play an important role in winning over African American supporters in South Carolina and beyond.

“Michelle Obama is a sister-sister and those black ladies in the beauty shops which she goes to and the black churches love her,” the president of the National Ten Point Leadership Foundation, the Reverend Eugene Rivers III, said. “The best political resource that Barack Obama has in South Carolina is an irresistibly attractive Michelle Obama who is a black Jackie O with brains.”