Why do more educated people tend toward centrism?

[This is Eharding, guys]

It is a well-known truism that places with a high concentration of well-educated people (e.g., GA-06, Manhattan, NoVa, Cambridge) tended to reject extreme right demagogues like Cruz and populist center-right politicians like Trump in favor of candidates more congenial to (though still very much incompatible with) the Democratic base like Rubio and Kasich. Likewise, places with a high concentration of well-educated people tended to be somewhat more pro-Hillary in the 2016 Democratic primary and much more pro-Obama in the 2008 Democratic primary than those with similar racial demographics. The question remains, why is this so? Why would better-educated people tend toward not the far left or far right, but the center? If you think the options listed by me are insufficient, please describe your hypothesis below.

[This is Eharding, guys]

Because "educated" people are usually rich, and rich people like to keep things the way they are.

Am doubtful. Look at Livingston County, MI, Litchfield County, CT, Suffolk County, NY, Staten Island, St. Charles' County, MO (rich counties that had a higher percentage go for Trump than Romney). See the FiveThirtyEight article on this.
http://fivethirtyeight.com/features/education-not-income-predicted-who-would-vote-for-trump/

[This is Eharding, guys]

They don't. Under certain circumstances they will vote for more "centrist" candidates (accepting the conventional media definition for a moment), but it's by no means a guiding rule. Simply look at the results from college towns in the 2016 Democratic presidential primary.

That is purely an age issue. In any case, results from college towns in the 2016 Democratic presidential primary appear to be correlated with the average income of the parents of those college towns' students. For example, Ypsilanti (Eastern Michigan University) went 66.8% for Sanders, Amherst (UMass Amherst) 66.3%, Ann Arbor (U of M Ann Arbor) 56%, Hanover (Dartmouth) 53%, and Cambridge (Harvard) 46.2%.

[This is Eharding, guys]

To be fair, didn't Obama's platform run left of Clinton's?

Yes. I was just old enough to remember the primaries back then (12 years old at the time). Obama dragged Hillary on her Iraq war vote and hit her pretty hard on NAFTA/trade deals and being too establishment and corporate friendly (noting that she was a corporate lawyer serving on the board of Walmart). Sound familiar? That's Sanders primary message and Trump's GE message against her as well.

One could argue that Obama's 2008 blueprint against Clinton was stolen directly by Sanders and Trump. That's why Trump and Sanders populism is part of a greater trend that's been in place since 2008 and in the post financial crisis political environment.

Timmy, part of this is revisionist history. Hillary demanded an immediate withdrawal from Iraq, Obama a gradual one. Obama opposed the individual mandate, Hillary supported truly universal healthcare. Obama ran very well in rich, well-educated southern suburbs and cities, Bernie did far worse in those. Despite Obama dragging Hillary on NAFTA, he did terribly in the heavily white working class areas of Ohio, much worse than Sanders did.
https://uselectionatlas.org/RESULTS/state.php?year=2008&fips=39&f=0&off=0&elect=1