When you refer to education levels are you implying that those with more education tend to be more left leaning?
This has shifted over time and I think it is somewhat ridiculous to say liberals are smarter or conservatives are smarter. What I think is being talked about here is education levels, not native IQ which is probably always fairly equally distributed (although very poor people might somewhat have lower IQ - possibly).
When I was young, better educated people tended to be wealthier and more conservative (business, country clubs, churchgoers, etc.). The working class tended to be more economically liberal (unions, distrust of big business, minimum wage, etc.), although generally fairly conservative on the social side.
Now that I am old, the better educated people seem more on the liberal side in most but not all parts of the US (more “woke”, minority rights, tolerant of alternative lifestyles, focus on health care, etc.). And the working class (whites anyway), less “woke”, less tolerant, focused on crime issues, more socially conservative.
Don’t think there is a right or wrong about it. It has shifted and evolved that way for lots of reasons. I am quite liberal and my best friend is very conservative. We “argue” all the time, but my sense is that we are pretty comparable intelligence wise. He might disagree.