How many times can the most important speech on race in America be made in one year? Probably one. Even though Barack Obama will accept the Democratic nomination for president on the 45th anniversary of Martin Luther King’s Jr.’s “I Have a Dream” speech, and even though you can practically see the goose-bumps in the mainstream media’s stories about Obama’s “march into history,” tonight’s acceptance speech will largely not be about race in America. This is because Obama has already squandered his oratorical share of American racial history on a speech vouching for a delusional race-huckster from Chicago named Jeremiah Wright. That’s a sad reflection on a night that, frankly, is goosebump-worthy for anyone who believes in the ideals of our nation’s founding.

In the Los Angeles Times, Michael Finnegan rightly notes “the historical weight of Obama’s address to party loyalists packed into a football stadium exceeds anything faced by those soon-to-be presidents when they accepted their parties’ nominations in 1960, 1980 and 1992.” But surely a good deal of that historical heft has already been drained by the exegesis on race in America that Obama delivered back in March. That speech was, after all, what “we have all been waiting for for a generation. Its ability to embrace both the legitimate fears and resentments of whites and the understandable anger and dashed hopes of many blacks was, in my view, unique in recent American history.” It was a speech that the New York Times editorial board compared to the seminal words of FDR and Lincoln. It was, lest we forget, “a moment that Obama made great through the seriousness, intelligence, eloquence, and courage of what he said. I don’t recall another speech about race with as little pandering or posturing or shying from awkward points, and as much honest attempt to explain and connect, as this one.” (It was also a cloaked defense of a rank paranoiac who Obama disowned in self-preservation a week later.)

Tonight, amid fireworks and confetti and framed by a plywood pantheon, Obama will keep his appointment with history. It will be a great moment for America, but a slightly less great moment for the candidate himself. Barack Obama’s candidacy is all about goosebumps and shivers and world-historical moments. We are all eager to gush over tonight’s fulfilled promise and when the first black Democratic nominee for president is on stage at Mile High Stadium I’m sure we all will. But think of the campaign triumph that tonight could have been if Obama had simply sidelined his whacked-out preacher instead of beautifully explaining away his bile.