barack_obama_10.jpg(AP) _ The principle that all men are created equal has never been more than a remote eventuality in the quest for the presidency. But now that Barack Obama has clinched the Democratic presidential nomination, that ideal is no longer relegated to some day.

Some day is now.

It is a history-making moment _ though Obama is not necessarily the candidate many might have expected to make that history. He is the son of a black father from Kenya and a white mother from Kansas. He's too young to remember the civil rights struggle, let alone to have been a soldier in the fight.

“He was impossible to anticipate,'' says Shola Lynch, director of a documentary about the 1972 campaign waged by Rep. Shirley Chisholm, the New Yorker who was the first black woman to vie for the presidency.

In a country whose self-identity has been warped by racial prejudice since the beginning, this moment has taken an eternity to arrive. Or, viewed over the spectrum of a long, painful history, relatively little time at all.

After all, it has been just 45 years since Martin Luther King declared his dream for a colorblind America, just over 30 years since Mississippi disbanded the sovereignty commission that fought to maintain segregation and deny blacks their rights.

Other notable black candidates have run for the highest office. Some waged serious campaigns that, at least when it came to the prospect of winning the nomination, were never taken seriously.

“I grew up and matured in the height of the civil rights movement and there was no thought then of a black man being president of the United States. We had barely begun to vote then,'' says Ronald Walters, who served as deputy director of the Rev. Jesse Jackson's run for the presidency in 1984.

“It was hard for us, even in the Jackson campaign, to get our arms around this, the fact that there would be a black president of the United States _ even though we were running,'' says Walters, now a professor of government and politics at the University of Maryland.

But even as they marvel at Obama's rise, Walters and others say it will take time to appraise what it says about the nation's political and cultural state of mind. Can he be elected? How long will it take before other viable black candidates _ not to mention women _ compete for the presidency?

Obama's likely nomination is a milestone, but it is not at all clear where that marker is posted. His ascendance could prove to be a fairly isolated event, the creation of extraordinary coincidences, or something more.

“The nation has come a long way,'' when a major party demonstrates its support for a presidential nominee who is not a white male, says Thomas J. Davis, author of the book Race Relations in America and a professor of history at Arizona State University.

But “what does it tell us aside from that fact, which we can see right before our eyes?''

Some may see Obama's success as marking a revolution in the politics of race. In fact, it's the latest incremental step _ albeit the most noticeable one _ in a gradual evolution.

By the early 1960s, pressure was building. Activists clashed with police in Selma, Ala., in a history-making demand for the right to vote. Congress passed the National Voting Rights Act to eliminate the literacy tests many Southern States used to keep black voters from the polls. That led to much greater black voter participation and the first significant entry of black candidates and office holders.

Change came, but slowly. In 1965, Massachusetts voters chose Edward Brooke for a Senate seat, but it wasn't until 1993 that another black candidate was elected to the chamber.

In 1972, Chisholm, a New York congresswoman, became the first black woman to pursue the presidency, waging a campaign to end the Vietnam War and give voice to the silent in the nation's policy-making. Jesse Jackson followed in 1984 and 1988, paving the way for the candidacies of Alan Keyes, Al Sharpton and Carol Moseley Braun.

Still, it wasn't until 1989 that Virginia made Douglas L. Wilder the nation's first black elected governor.

A majority of Americans said the country was ready for a black president, but that was far from making it reality.

“The fact is that there were no African Americans who were in a position to run for president at that time so what people would say was really pretty irrelevant,'' said David Bositis of the Joint Center for Political and Economic Studies, a think tank focused on issues important to black Americans.

Voters did not really begin to contemplate the idea of a black president as anything beyond an abstract until the 1990s when Gen. Colin Powell, chairman of the joint chiefs of staff during the Gulf War, gained wide admiration.

Now, the irony of Obama's achievement is that much of what it represents is not about the color of his skin.

Obama, at 46 too young to remember the civil rights era, has run a race that, at least when possible, has been deliberately not about race.

He steered clear of a campaign like Jesse Jackson's, which shaped itself as a fight for the rights of minorities and the poor. Instead, he promised an era of change, an idea that found broad support among different groups of voters. He excluded many of the civil rights leaders and others _ from Jackson to Al Sharpton _ who would have defined him as a black candidate.

He spoke about himself not primarily as a black man, but as a man whose story was uniquely American.

“Was it about race? No, it was about electability,'' Walters said. “The racial aspect of his agenda is missing, the racial politics are missing. So really all you have left is the symbol of the person.''

The result is a prospective nominee whose candidacy is weighted with the possibility of cultural significance, but maybe not in the way that might have been imagined. It is less a testament to rising black political fortunes than to the power of a fast-changing social dynamic.

In the ranks of black politics, the baton is being passed from leaders rooted in the fight for civil rights and social activism to a new group of young, educated and energized politicians with their own point of view.

At the same time, the nation's electorate is less strictly defined by black and white. That is partly the result of immigration and the growth of other groups of voters. But it is also a sign of assimilation, intermarriage and the arrival of younger voters with different sensibilities.

“America is in the midst of a significant demographic shift and Barack Obama in his person represents a significant element of that shift,'' Davis says.

Today's teens have much more experience with people of other races or mixed races than did their parents. While Obama's story doesn't reflect the typical African-American experience, it does speak to this new generation that is less polarized by race _ tomorrow's voters, Bositis says.

His candidacy should act as a signal to these voters, whether they're young black men or young white women, that people like them can dream, realistically, about being president, observers say.

Politics is a lagging indicator of that shift. But Obama's message of change taps into it.

“People are thirsting for a new face, a new voice and he's set to go,'' Walters says.

The Obama candidacy reflects a country that is at, or at least near, the point where a generation that has long held on to power must cede the spotlight.

But the general election campaign to come is likely to remind us that the nation, despite its maturation, remains conflicted about race.

“Race is so tender and temperamental an issue in U.S. society and politics,'' Davis said. “It won't be a major issue overtly, but under the covers it's going to be an issue, absolutely.''

In recent polls, about three of every four voters said the country is ready for a black president. Obama's nomination offers the first chance to put that assertion to the test.

Many black voters remain skeptical. Significantly fewer of them say they believe the country is ready. Their doubts are a reminder that Obama's claim to the nomination, while a milestone, does not resolve the country's long entanglement with racialized politics.

It reminds Walters of a day, 50 years ago, when he led the nation's first sit-in demonstration at the whites-only Dockum Drugstore lunch counter in his hometown of Wichita, Kan. Back then, the prospect of a black president was unimaginable.

Now, with Obama one step away, “it's tremendous pride in the fact that this is occurring,'' he says. But that pride is tempered by “a sense of realism and caution about what can be achieved.''