You get what you pay for

[timelets]

High-school education in the US is free, but college education is not. Also, high school is not a choice, while college is. In short, people choose to have more education and are willing to pay for it. If we think about education as an investment into one's future it should not be surprising that the more education you get and the more you spend on it, the less likely you'll be voting for Trump.