I think you're right about the IQ. I believe Nate Silver addressed the fact that Trump voters were generally more well off and educated than supporters of Hillary and Bernie.

Also, Democrat policy making going back to Ted Kennedy has favored poorly educated immigrants from Southeast Asia, Africa and South America in particular. This is a fact and worth researching if you're at all confused about it. Also, these immigrants have been shown to vote roughly 4 to 1 in favor of Democrats.