When are you dumbasses going to learn that the very last thing you should do is underestimate your opponents?
Also, if you can't figure out why your opponents think the way they do without resorting to they're stupid, deluded or evil, you are hopelessly partisan.
I think it's more complex than that, many people vote or think as they do, because of mind blowing stupid reasons. But this are individuals, demographic groups vote as they do for very good reasons. Sometimes those reason are short sighted, but they're never stupid.