"The Presidency," Franklin D. Roosevelt told a reporter shortly after he was elected in 1932, "is pre-eminently a place of moral leadership." We don't know yet whether Barack Obama can get himself elected president, much less prove a success in office. He could get swamped by unanticipated problems or suffer from crippling flaws we haven't seen yet. All presidents are blind dates. But Obama is showing signs that he could project his voice in the theater of the American presidency. Even if his legislative agenda founders, he might be able to help the nation raise its sights in new ways. You might think of it as the Obama Dividend.

As the afterglow of last week's landmark Philadelphia speech on race fades, even many conservatives agree with liberal editorial writers that Obama's approach was brilliant. I'm skeptical of that adjective and reluctant to hazard a guess about the political impact of the speech on blue-collar whites. Until the Pennsylvania primary on April 22, we won't know if they even heard about the story of his white grandmother, or how he gave voice to white frustration about affirmative action and busing. But I do know that the speech was "presidential" in the best sense of that word, and for reasons beyond a tone of gravitas and a backdrop of American flags. To succeed in a crisis (and the Rev. Jeremiah Wright Jr.'s inflammatory sermons were at least a mini-crisis for Obama), presidents must do more than rally the country enough to win backing in polls for a course of action. That's relatively easy. The hard part is using the bully pulpit to instruct and illuminate and rearrange our mental furniture. Every great president has been a captivating teacher. By talking honestly and intelligently about a subject that most Americans would rather ignore, Obama offered a preview of how he would perform as educator-in-chief.

Obama's unique assets have usually been viewed in international terms. The election of President Barack Hussein Obama would blow the minds of people in the Middle East and other regions, and help restore American prestige. Of course, given unpredictable global events, the Obama Dividend abroad may last about as long as the much-hyped post- cold-war "peace dividend." It could pay returns for only weeks or months instead of years. Just look at Kenya, where one tribe involved in the recent unrest loves Obama (because his father was a member), and the other tribe has no use for him.

But in the United States, black opinion is now nearly unanimously behind Obama, with as many as 90 percent supporting him in the primaries. While Obama can do much to guide white Americans toward a better racial future and a greater appreciation that poor kids are not, as he says, "someone else's children," his most exciting potential for moral leadership could be in the African-American community.

Remember the 1998 movie "Bulworth," where Warren Beatty plays a U.S. senator suffering a nervous breakdown? When Beatty's character tells astonished black Democrats that it's time for them to "put down the chicken and the malt liquor," it's final proof that Jay Bulworth is crazy and suicidal. But consider what happened late last month in Beaumont, Texas, when I covered Obama speaking before an African-American audience. A woman asked about health care and Obama explained how, for the first time in human history, thousands of obese children, many of them black, were being diagnosed with adult-onset diabetes—a disease that is killing millions and helping bankrupt the health-care system. He told the crowd that kids couldn't keep on "drinking eight sodas a day," then went in Bulworth's direction. "I know some of y'all got that cold Popeye's [chicken] out for breakfast. I know," Obama said with a smile. He continued: "That's why y'all laughing. You can't do that. Children have to have proper nutrition. That affects also how they study, how they learn in school … It's not good enough for you to say to your child, 'Do good in school,' and then when that child comes home, you got the TV set on, you got the radio on, you don't check their homework, there is not a book in the house, you've got the videogame playing." Instead of being jeered, he was cheered wildly.