Taking on Obama wasn't political suicide. But it was very costly for Dr. Keyes personally. And those costs came at the hands of three groups of people:
Democrats
The liberal media establishment
Traitorous Republicans
Now, let me give you the order in which they were the most vicious and hostile:
Traitorous Republicans
The liberal media establishment
Democrats
'Course, the Dems didn't HAVE to do much of anything...traitorous Republicans and the hostile liberal media had already done the work for 'em.
Illinois is the most politically screwed up state I've ever seen...the corruption and lack of principle is in both parties.
However, you didn't address the primary against Bush scenario.