It was a deeply substantive speech, full of policy detail, full of people other than the candidate, centered overwhelmingly on domestic economic anxiety. It was a liberal speech, more unabashedly, unashamedly liberal than any Democratic acceptance speech since the great era of American liberalism. But it made the case for that liberalism - in the context of the decline of the American dream, and the rise of cynicism and the collapse of cultural unity. His ability to portray that liberalism as a patriotic, unifying, ennobling tradition makes him the most lethal and remarkable Democratic figure since John F Kennedy.
What he didn't do was give an airy, abstract, dreamy confection of rhetoric. The McCain campaign set Obama up as a celebrity airhead, a Paris Hilton of wealth and elitism. And he let them portray him that way, and let them over-reach, and let them punch him again and again ... and then he turned around and destroyed them. If the Rove Republicans thought they were playing with a patsy, they just got a reality check.
He took every assault on him and turned them around. He showed not just that he understood the experience of many middle class Americans, but that he understood how the Republicans have succeeded in smearing him. And he didn't shrink from the personal charges; he rebutted them. Whoever else this was, it was not Adlai Stevenson. It was not Jimmy Carter. And it was less afraid and less calculating than Bill Clinton.