I don't recall the exit polls being that far off in 2004. I think the early exit poll returns were in some states, but that can be explained by different voters voting after work. But I agree with the overall point you're making that it's doubtful that Trump improved among hispanics or other minorities and his win in the electoral college/narrow loss in the popular vote was the result of uneducated whites jumping to him in droves. Not sure about typical Republicans coming home though, as he struggled in suburbs that have always tended to vote Republican.
Hm. That's what I saw somewhere on Atlas (probably unreliable) about Kerry winning Ohio. I'll probably edit.