You could be right about anti-Southern bigotry. Do you remember how well Gerald Ford ran against Jimmy Carter in the northeast?
Ford did quite well in the northeast. He carried 4 of 6 New England states (CT, ME, NH, VT). Carried NJ and only lost NY by a margin of 52-48% (in fact, NY & TX's margins were nearly identical for Carter, as he carried both). These are percentages the GOP would kill for up there today.