Washington ? In the days following Barack Obama’s address on race last week in Philadelphia, there was broad agreement among politicians and journalists that “A More Perfect Union,” as he titled his speech, was the most important he has delivered since his keynote at the 2004 Democratic National Convention.

It was much more than that. It was a politically ambitious, intellectually impressive and emotionally compelling argument – ironically, one that may fall short of achieving two of its objectives but still be of great benefit to Obama and the country.

The immediate purpose – and the urgent need that prompted him to schedule the appearance – was to douse the controversy that had erupted over the repeated TV and YouTube showings of inflammatory excerpts from the sermons of Obama’s longtime friend, mentor and former pastor, the Rev. Jeremiah Wright Jr.

Despite the praise for Obama’s Philadelphia speech, the carnage started by Wright is likely to continue or recur, not only because there are some who despise the candidate they call “Barack Hussein Obama” and are eager to use this against him, but because there are many others deeply offended by his preacher shouting “God damn America!”

I was one of those, and even after hearing African-American friends argue that the style of the black church and the reaction in that largely middle-class congregation in Chicago should alert us that Wright is hardly outside the mainstream of his community, he still seems a world away from the calm and considerate image Obama himself presents.

But after Obama had thoroughly repudiated Wright’s offensive comments as “not only wrong but divisive,” he added this striking sentence: “I can no more disown him than I can disown the black community.”

It reminded me of Shelby Steele’s argument that Obama is a “bound man,” trapped by his need to emphasize the black half of his mixed-race heritage for his own psychological security, but a man whose career and ambitions have taken him deep into the larger white world.

That inner tension would be a continuing challenge to Obama, even if Rev. Wright had never sounded off.

The second goal for Obama was to stimulate a healthier dialogue among all Americans on race. I went to San Diego in 1997, when Bill Clinton launched his ambitious effort “to lead the American people in a great and unprecedented (yearlong) conversation about race.” Clinton’s intentions were honorable, but long before the year was up, both he and the public had been distracted by more immediate concerns, and the initiative dwindled into an academic exercise that produced only a quickly forgotten volume.

So if Philadelphia is unlikely to end the controversy over Obama’s relationship with Wright or stimulate a new national dialogue on race, what is the real significance of what Obama did there? All year long, he has been writing and giving exceptionally effective addresses. But, almost without exception, these speeches have been campaign rhetoric. This, however, was largely a presidential address – and on the touchiest issue in American life.

It compellingly contrasted the ugly history of slavery and segregation and its debilitating effects on the black community to the inspirational saga of Obama’s own Kenyan-born father and Kansas-bred mother. It explained how that heritage, plus the opportunities only America could provide, enabled their son to achieve so much so fast.

It included a remarkably sensitive rendering of the frustrations not only of blacks but, equally, of working-class whites “who are anxious about their futures and feel their dreams slipping away.” Obama understands their opposition to busing and affirmative action, even as he urges them to look beyond their justifiable resentments and help end the “racial stalemate we’ve been stuck in for years.”

It is rare that a president addresses the racial issues with anything like the honesty Obama did. You might have to go back to Lyndon Johnson in his 1965 “we shall overcome” speech, urging Congress to pass the Voting Rights Act, or the same president 40 years ago, after the nation was rocked by the riots following the murder of Martin Luther King Jr. In recent decades, few presidents other than Ronald Reagan have been able to lead the nation by the power of their words.

What Obama showed in Philadelphia is the potential similarly to inform, educate and inspire people, if he is allowed to fill “the bully pulpit” of the presidency. If that is what people sense, this will indeed make the Philadelphia speech a historic occasion.