It was the fist bump heard around the world. As Sen. Barack Obama walked onstage in St. Paul, Minn., after clinching the Democratic nomination...

WASHINGTON — It was the fist bump heard around the world.

As Sen. Barack Obama walked onstage in St. Paul, Minn., after clinching the Democratic nomination Tuesday night, he and wife Michelle hugged and then, gazing into each other’s eyes with knowing smiles, gently knocked knuckles.

He also gave her a playful pat on the butt, but it was the bump that got everyone talking. “That is the picture!” exulted one poster on the Jack and Jill Politics blog, which offers “a Black bourgeois perspective.”

“When I saw them give each other dap, I was like ‘Hell yeah!’ “

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Dap, fist pound, whatever you want to call it, it’s something Americans are not used to seeing on the national political stage.

“It thrilled a lot of black folks,” said author and commentator Ta-Nehisi Coates, who blogs at Why? Because it’s the kind of gesture that, while commonplace among African Americans, was generally stifled by earlier generations of blacks working their way into the corporate or political worlds for fears “about looking too black,” he said.

But Obama “is past that. … He wears his cultural blackness all over the place. … It’s liberating to be able to run for president as a black man. … Barack is like Black Folks 2.0.”

NBC Nightly News anchor Brian Williams asked Obama on Wednesday about the dap, noting that Michelle had “tried to give her husband a fist pound the way a lot of Americans do, the way a lot of couples do. The only problem it’s an inside move shared in front of 17-and-a-half thousand people in the arena and millions watching at home.”

Obama’s answer: “It captured what I love about my wife. There’s an irreverence about her and sense that for all the hoopla, that I’m her husband and sometimes we’ll do silly things and yet she’s proud of me and she gives me some credit once in a while that I actually pull some things off.”

It also signaled that, for all they have sacrificed during the campaign — including membership in the church where they were wed and their children baptized — the Obamas are still cool, still comfortable in who they are.

But, as “Town” asked in a posting on Jack and Jill Politics, “Which one will claim that Barack and Michelle were using some secret black-power fist gang signal to call blacks worldwide to arms? Sean Hannity? Geraldine Ferraro? Pat Buchanan?”

In fact, said Anthony Neal, a professor of black popular culture at Duke University, the dap probably does trace its early origins to the black-power salute of the 1960s.

But it morphed into what it is today — lateral instead of vertical — in the intersection of hip-hop and the National Basketball Association in the 1980s.

In the years since, it has become familiar beyond the black world to many Americans younger than 50, especially to anyone glued to a television as professional athletes congratulate each other on exceptional performance.

Black people and those younger than 50 are a demographic that in the past few months has come to be known by another name: Obama voters.