How could so many people be so blind?
Eggheads in psychology could probably dissect the reason for the cognitive disconnect. Suffice it that the Rats exploited this phenomenon to punk the system slyly. Had the GOP candidate been, say, Romney or Huckabee, the Rats probably would have given the nod to Hillary and tossed Obama under the bus, because either of those quasi-Pubs would at least not have been the Kentucky Fried Gentleman.
I think many people wanted so badly to have an African American President, simply to show they were not racists, that they voted for him. The press didn’t cover the things that should have risen red flags, and he had a weak opponent who the Republicans didn’t like very much. At least that’s my take.