Once the Democratic Primary is over and McCain goes under the microscope, there is no way any sane individual would vote for him.  So we have just have to figure out how big the insane demographic is in the electorate for the GE and add that to the racist individuals to get a estimate of what the Obama vs McCain GE match-up would look like.  Since insane and racist people can hide in plain sight I don't know how you would actually poll for them.  My guess is that we can use Bush's approval numbers to accurately capture this demographic which I think is at 28%.  So Obama wins GE by capturing 78% of the vote and probably every state.  But lets just keep this between us.