That's because "higher" education has changed. Today, many go to college only to get thoroughly stupid studying under radical Leftist, crazy, whack-a-doodle professors. They attain a level of stupidity not found in nature by the time they graduate. So, nothing really has changed. Idiots are still voting Democrat.
That's certainly been a common talking point among right-wingers, eager to explain away the strong correlation between educated societies and left-leaning societies. But one fascinating thing about the phenomenon is that it existed even before the correlation held true at the individual level.
For example, as recently as the 2012 election,
Republicans were doing better with those individuals who have college degrees. Romney won 53% of college graduates, and Obama won just 43%. Yet, even as that correlation favored Republicans at the individual level, it favored Democrats at the societal level: the most educated states and communities went for Obama.
Then, as now, Massachusetts was the most educated state, whether you measured by percentage of people with a bachelor's degree, percent with a degree from a highly competitive university, percent with an advanced degree, or just in terms of the quality of high schools in the state (it has dominated NAEP scores for decades). And, even with Massachusetts being Romney's home state, Obama manhandled him there, just as he did in every other highly-educated state... a margin of well over 20 points, in fact.
I find that really interesting: that Romney could do better with college-educated people at the individual level, while being completely uncompetitive in highly educated states and localities. Why?
There's a critical-mass issue there. When you have a critical mass of well-educated people in an area, the voting tendencies of both the educated and the uneducated in that area tend to move left. Or, to put it the other way, when there's a critical mass of ignorance, both the educated and the uneducated in the area are more likely to vote Republican.
I suppose some of that may come down to the fact that liberal politics are based around collective action, and how appealing collective action is going to seem depends in large part on who you see around you. If you're surrounded by ignoramuses, you're more likely to figure you're better off going it alone, and you'll tell the government to butt out. If, on the other hand, you're surrounded by well-educated people, you're more likely to think banding together on something is a way to make the whole better than the sum of the parts.
To put it in really simple terms, imagine you're in a gym class and you have a choice of playing a team sport like basketball, or an individual one like distance running. If you look around you and see a bunch of uncoordinated, unmotivated slobs, the idea of your success being dependent on them is going to look less attractive and you'll go for the individual sport. But if you look around and see a bunch of strong athletes, the team sport may seem like a better way to motivate each other and come together for something special.
