From left, Brown Chapel AME Church pastor James Jackson; Democratic presidential candidate Sen. Barack Obama, D-Ill.; Rep. John Lewis, D-Georgia; and the Rev. Clete Kiley hold hands and sing at the end of a church service, Sunday in Selma, Ala.

Selma, Ala. ? Sen. Barack Obama, D-Ill., describing himself as “the offspring of the movement,” paid homage Sunday to the civil rights protesters whose violent beatings here at the hands of state troopers and sheriff’s deputies 42 years ago sparked national outrage and led to legislation ensuring the voting rights of African Americans throughout the South.

Just a few blocks away, Sen. Hillary Rodham Clinton, D-N.Y., claimed the same inheritance, describing the civil rights movement as “the gift that keeps on giving” as it propels new types of politicians onto the national stage. Their joint appearance at the annual commemoration of one of the most famous moments in the civil rights struggle embodied the historic nature of a presidential race in which a black man and a woman lead the Democratic field.

The two presidential candidates spoke at separate Sunday morning services and later joined in the ritual march across the Edmund Pettus bridge, led by Rep. John Lewis, D-Ga., who as a young civil rights leader was beaten on the bridge with other protesters on the morning of March 7, 1965, as they began a march to Montgomery for voting rights. Hillary Clinton marched with her husband, former president Bill Clinton, who came to Selma to be inducted into the National Voting Rights Museum’s hall of fame. It was the first time Clinton and her husband appeared together at a major event in the 2008 campaign, and an appearance much-debated in the Clinton campaign before it was announced Thursday night.

In the days leading up to the commemoration of “Bloody Sunday,” advisers to both Obama and Clinton had insisted it would not be a day for politics. But their presence in Alabama signaled the extraordinary importance of black voters in the upcoming Democratic primaries, with recent surveys indicating that Obama is jeopardizing Clinton’s lead in the race by gaining among blacks. And any pretense that it was not part of the presidential campaign was dropped as they day went on. Supporters carried signs for the two campaigns, former president Clinton joked about the “rainbow coalition” of candidates on the Democratic ballot, and Rep. Artur Davis, the Alabama Democrat who represents Selma, unabashedly introduced Obama in his keynote address at Brown Chapel AME Church as the next president of the United States.

The crowd in and around Obama’s appearance was decidedly larger – his audience included 15 members of Congress, compared with four who went to hear Hilary Clinton. Obama, who was three years old at the time of the Selma clash, used his keynote address to mark his place in a younger generation of black Americans who no longer march in the streets – but still, in his words, are required “to fulfill that legacy, to fulfill the obligations and the debt that we owe to those who allowed us to be here today.”