Let's just say if Gillum blows it, I will consider it evidence of a Bradley Effect and that in the Age of Trump, it is a real thing as segregation and exclusion have become mainstream positions again.
But if segregation and exclusion were mainstream positions, the Bradley Effect by definition wouldn't exist! The whole concept of the Bradley Effect is predicated on people lying about planning to vote for a black candidate because they want to seem socially acceptable while in fact having racist motivations to vote for the black candidate's opponent. But, if there's no social desirability bias because racism is mainstream, the Bradley Effect can't exist.
Of course, it never existed anyway, but oh well.
Then again, were in kind of a weird time where overt racism is still frowned upon but racism might becoming popular.