We conservatives have principles. Principles are used to screen and filter information we receive. What principles to liberals have? Although their motives are altruistic, they make the mistake in thinking their altruistic actions can transcend into some form of government benevolence.
Maybe I have not met enough "common liberals", since most that I know are pretty bright.
Intelligence takes different forms. You could invite them on this forum to challenge me. Many southern people are democrats because of their immediate heritage. If they examine their belief systems, perhaps most of them will realize they are actually conservatives.