George Mason University economist Bryan Caplan has long argued that one of the core facts about American politics is that voters tend to be irrational, and that it is easy for them to be so given that they don't bear too much of the costs of being irrational while enjoying all the benefits.

He expressed this thesis at length in his book The Myth of the Rational Voter, a book excerpted here at Reason in the cover feature "The 4 Boneheaded Biases of Stupid Voters (And We're All Stupid Voters)."

I applied Caplan's thesis to the rise of Trump back in August, before the naive such as me knew he was going (nearly) all the way.

While Caplan insists that this crazy year doesn't prove his point, which was correct all along, it does demonstrate it pretty vividly, particularly with the surprising rise of Trump and Bernie Sanders, who exemplify two of the irrational biases he pinpointed. (This article by Caplan I'm summin up is a couple of months old, but I only came across it today and its observations are all the more pointed as Trump's long march continues.)

While the public perennially exhibits what I call anti-market and anti-foreign biases, 2016 is egregious. Sanders is anti-market bias personified, Trump is anti-foreign bias personified. Sadly, my claim that the median American is a "moderate national socialist—statist to the core on both economic and social policy" looks truer than ever.

Caplan thinks Trump's political entrepreneurial genius lies in fully embracing the median GOP voters anti-foreign bias more than other candidates, slightly constrained by elite opinion, have previously done. "it now looks like anti-foreign bias matters more to them than all other issues combined," is Caplan's take on Trump's triumph.

Caplan was more optimistic about our political system's ability to not let the likes of Sanders and Trump get so far. "In 2016, one of the main dilution mechanisms has badly failed: Using social pressure to check and exclude hard-line demagogues," he thinks.

But he hasn't given up hope; our system has other sanity brakes on public irrationality. Among them:

(a) While the public often likes crazy policies, they resent the disastrous consequences of those crazy policies. This gives politicians a strong incentive for felicitous hypocrisy once they gain power—especially when contemplating policy change. (b) The median voter has a short attention span, so relatively sane elites have more influence in the long-run than the short-run. (c) Old-fashioned checks and balances: Congress, the Supreme Court, and state governments make it hard for Sanders or Trump to fulfill their promises even if they want to.

If American voters were rational, Caplan believes, "Sanders and Trump wouldn't stand a chance. None of the candidates would survive serious scrutiny, but Sanders and Trump would be thrown out as soon as they delivered one short speech."

Caplan also plays with relative perceptions of cultural decay, noting that if Trump were Hispanic, "Opponents of immigration would plausibly fear that El Donaldo is a classic strongman plotting to turn the U.S. into a banana republic. And they would hasten to the inference that Hispanics are fundamentally authoritarian and unfit for democracy. "

Who is fit for democracy? This election raises that question, good and hard.