But Mr. Obama claims to represent something different from old-style politics -- especially old-style Chicago politics. And the senator is embarrassed enough by what he did that he misrepresents it in the prologue of his political memoir, "The Audacity of Hope."
He attributes his 1996 victory to his message of hope, and his exhortations that Chicagoans drop their justifiable cynicism about politics.
The act of throwing an incumbent off the ballot in such a fashion does not fit neatly into the narrative of a public-spirited reformer who seeks to make people less cynical about politics.
It is telling that, when asked at the Saddleback Forum last weekend to name an instance in which he had worked against his own party or his own political interests, he didn't have a good answer.
The most dramatic examples of Mr. Obama's commitment to old-style politics are his repeated endorsements of Chicago's machine politicians, which came in opposition to what people of all ideological stripes viewed as the common good.
In the 2006 election, reformers from both parties attempted to end the corruption in Chicago's Cook County government. They probably would have succeeded, too, had Mr. Obama taken their side. Liberals and conservatives came together and nearly ousted Cook County Board President John Stroger, the machine boss whom court papers credibly accuse of illegally using the county payroll to maintain his own standing army of political cronies, contributors and campaigners.