Barack Obama has already soared to a place that no black politician has ever reached. He sits on a crest above the vast expanse of the national electorate, not squeezed into a niche, not strapped for cash, a sudden comfortable surprise among the presidential front-runners. They say he caught lightning in a jar. Some say the lightning catcher can win.

Every African-American politician who has ever dreamed of leading the country knows how difficult it is to occupy this space. For decades, there has been a rolling conversation in black political circles about who and when and how to run for president. In 2000, President Clinton’s former chief adviser on race, Christopher Edley Jr., was asked to speculate about the prospects of a black president by 2020.

“I’m pessimistic about that,” said Edley, who by then had returned to his Harvard Law School professorship. “I think we will see a woman or Latino before we see an African-American.”

It wasn’t just that Edley had peered over the horizon and taken note of the growing Latino population. Or that he had observed Hillary Clinton up close and could sense her potency. More than anything, Edley knew that the upper echelons of elective office — particularly the Senate and the governor’s mansions, which produce the most viable presidential candidacies — were “still very segregated territory,” as he put it. So he believed that winning the presidency would be tougher for a black politician than for anyone else.

Edley, now dean of the Boalt Hall law school at the University of California, Berkeley, was reminded last week of his previous assessment. “Wow,” he said, followed by a long pause. “I hope it’s evidence that I’m a lousy prognosticator, because the evidence now is there is a lot more capacity for hopefulness among the electorate than I had thought.”

Obama is a former student of Edley’s at Harvard Law, and Edley is now an informal adviser to Obama’s campaign — “a tough thing for me,” he says, because he feels close to the Clintons, and his wife, Maria Echaveste, who also was a top official in the Clinton White House, is backing the senator from New York. As for Obama, Edley describes himself as both “giddy” and “a bit wary.” “I pinch myself at least once a day, I really do,” he says, “because a part of me really believes what I said eight years ago — that it is fundamentally implausible (for an African-American to be president). But day by day, his success is proving me wrong. But I’m almost afraid to believe.”

No Democratic or Republican presidential candidate has raised more money than Obama ($78.9 million through the last filing period, ending Sept. 30). Only Sen. John McCain, R-Ariz., has a higher favorable rating nationally — he’s at 53 percent, Obama is at 49 percent in the latest Fox News/Opinion Dynamics poll. And polls show Obama deadlocked with Clinton in Iowa and a close second to her in New Hampshire, the first two Democratic nominating competitions.

Whether enough voters can envision Barack Obama in the Oval Office will be revealed shortly. But some black politicians believe the time is right, as the country has witnessed the gradual rise of African-Americans in leadership roles — from coaching major sports franchises to presiding over corporate boardrooms. Breakthroughs in the popular culture, where many Americans form their impressions of each other, have been among the hardest to achieve.

Norman Jewison, who directed the 1967 hit movie “In the Heat of the Night,” recalled that some newspapers refused to take ads for the film, which featured Sidney Poitier as a sharp-minded detective from Philadelphia investigating a murder in a Southern town. The movie went on to earn five Oscars, including one for Best Picture. “I think (the film) woke up a lot of people in the Deep South,” Jewison says. “I don’t think they’d ever seen a black character on the screen as smart and talented as Sidney.”

More than three decades later, actor Dennis Haysbert was cast as David Palmer, a US senator who is elected the nation’s first black president in the television drama “24.” When Haysbert encounters strangers who recognize him, it is often this role that they want to discuss. “I’ve lost track of how many times people have asked me to run for president,” Haysbert says, adding that he believes the role had “a major impact” on how black politicians are perceived, “simply from the feedback I get from people from all walks of life.”

And yet there are statistics that are not so heartening. Less than 4 percent of the nation’s elected officials are black, and 90 percent of them represent predominantly black or predominantly black-and-Hispanic constituencies. Thus, not many black politicians have won elections when the majority of voters were white. Only three black US senators and two black governors have been elected since Reconstruction.

As a consequence, only a handful of blacks have even dared to run for president, and virtually all them are civic activists such as comedian Dick Gregory, whose 1968 write-in campaign garnered just over 47,000 votes, perennial third-party candidate Lenora Fulani, and the Rev. Al Sharpton, whose 2004 Democratic campaign fizzled. The Rev. Jesse Jackson? We’ll get to him in a minute. “We’ve always been conflicted about this issue of running, because the heavy hanging cloud has been that a black can’t win,” says University of Maryland political scientist Ron Walters, who was Jackson’s top issues adviser during his 1984 campaign.

When exactly, though, is one ready to run for president? In 1972, New York Rep. Shirley Chisholm became the first African-American of stature to launch a presidential campaign. To some, her bid seemed more a statement of feminist politics than of racial politics. But its historical significance was recognized far and wide.

Richard Hatcher, then the mayor of Gary, Ind., recalls a tortured conversation with Chisholm the night before his city was to host the National Black Political Convention. The gathering would bring together thousands of black activists and officeholders from across the country to develop a black political agenda. Hatcher wanted Chisholm to come, but she was torn. The convention, she knew, would draw many militants and others who operated outside the mainstream of politics. Some, in fact, were determined to form an independent black political party. Chisholm worried that she might be rebuffed if she went, and that the rejection would hurt her candidacy.

Running under the slogan “Unbought and Unbossed,” Chisholm arrived at the Democratic National Convention in Miami with 151 delegates pledged to her and was given a coveted speaking slot. That in itself was progress. Several black politicians recalled earlier conventions when they had no access to the backstage meeting areas where all the important deals were cut.

Meanwhile, in the Republican Party, Sen. Edward Brooke of Massachusetts had quietly begun thinking of himself as a future president. As the first African-American to be popularly elected to the Senate, in 1966, he had quickly become a national star, called on to give speeches and appear at fundraisers across the country. According to Brooke, Michigan Gov. George Romney talked to him about a Romney-Brooke ticket in the early phases of the 1968 presidential race.

Romney’s campaign imploded after the governor made some ill-advised remarks about being the victim of “brainwashing” regarding the Vietnam War. But the Romney overture got Brooke to pondering his own ambitions. “Why couldn’t I be president of the United States? Is it too soon? How strong would the support of blacks be? Would I be acceptable to white voters in the South and Midwest as I assumed

With a week to go before the Iowa caucuses, Illinois State Senate President Emil Jones Jr., one of Obama’s political godfathers, is reminded of a story. It is from September 2004, when Obama was campaigning for the Senate in an overwhelmingly white, rural part of the state. Several thousand had gathered to see the Democratic nominee. After Obama spoke, an 84-year-old white woman approached Jones. “I hope I live long enough,” she said, according to Jones, who is black. “This man is going to be president, and I want to vote for him.”

It was Jones’ first glimpse of Obama’s broad appeal, and he didn’t share the anecdote with the candidate. But he wondered: Might it actually happen?

“It was really amazing,” Jones says, adding: “What happens is folks try to pigeonhole you, and he would never let folks pigeonhole him.”