Keyes does not do nearly as well you as you would hope. You can find the IL senate debates between Keyes and Obama in 2004 on Youtube.
I wouldn't have believed it, but it's true. No one can beat Keyes on substance, but it is possible to beat him, or at least fight him to a draw, with rhetorical style. Obama answered every jab in his calm, soothing, "let me make this perfectly clear," voice. His demeanor never changed. And his answers, which were devoid of substance, were full of platitudes.
It takes great effort to cut through Obama's gooey outer coating to get to the empty inner shell. Most opponents suffocate in the goo.