Why do politicians that claim to be so smart base their economic assumptions on what they hear from pundits?
Only two reasons; they really are stupid
or they found an issue that they can be a demagogue with, with the assumption that most people are ignorant and will believe they are making a good point; which between Hillary and the Dim base is probably a fare assumption to make.
They know their base. I don't ever bring it up, because I can't prove it, but years ago, I read a study that claimed the Dems average education was less than High School level. I thought that can't be right with all the News media and college professors, but then they pointed out the number of unwed mothers, drug addicts, welfare queens, union knee breakers, and other constituents that hung on their every word. Recently there has been an article pointing out the Hollywood left that was a waiter before becoming rich and somehow knowing all about global warming after they became rich.
I have described them as "being kept on the Democrat plantation" by the liberal elite. The elite don't have any common sense, and the slaves just say "yes Massah".