I think most educated people tend to vote more liberally, but its not due to indoctrination, its the nature of being an educated person, you understand so realities.
I tend to disagree with that thought. Colleges definitely indoctrinate. They did when I went (and laughed at my professors liberal beliefs) and they do now as I have warned/prepared my son ahead of time for such. It is extremely rare to have a professor present both points of view as fact. It is even more extremely common for a professor to present the liberal POV as gospel.
Also, compare degree areas and how someone votes. Compare those with mathematics/engineering degrees to those with history and/or philosophy and/or liberal arts degrees. I’d bet they have quite different political philosophies and as a result vote very differently. I have several Indian (not Native Americans) friends/acquaintances with degrees in math and engineering and to a person, most vote conservatively in their respective districts and states. Anecdotal, yes, but I have yet to see anything that makes me think differently.