Rational people tend to vote rationally. They study the candidates' platforms and choose the person who will benefit them the most. Being rational, they understand that the good of the many often outweighs their immediate personal needs or desires.
Most people do not vote rationally.
They are instead motivated by a very narrow sense of affiliation. They choose the candidate who they believe is one of their own, even if that person does not serve their economic well-being or the well-being of the nation (or the world). White racists will do without healthcare for their families if it means depriving African-Americans and Hispanics of healthcare.
Affiliation voters are driven by fear and spite — fear of the other and spite against anyone who threatens the integrity of their narrow circle.
Although Bernie Sanders is a true populist, in 2016 he would have lost the rust belt (and most likely the popular vote) to Trump, who knows better than Sanders (or Clinton) how to manipulate affiliation voters.
Trump’s bedside book was the Speeches of Adolph Hitler. Trump is not a Nazi or a fascist (he’s too petty and mean; a true Nazi would have read Mein Kampf). Trump simply wanted to learn how a demagogue could seduce the affiliation voters of Germany.
If Trump was a true populist, why did 97 percent of African-American women vote for Clinton (who was certainly no populist)? More than any other group, they understood the menace behind Trump’s affiliation message and voted for the good of the nation. White rust belt voters, however, voted for the man who sounded like one of them, who would protect them from terrorists and transsexual bathroom users.
If Democrats are to defeat Trump and congressional trumpskis in 2020, they have to create a sense of affiliation with voters (and it should be genuine). It’s not enough to be the Non-Trump (as Clinton discovered). Otherwise, they’ll lose again, no matter how rational their platform is, no matter how good they would be for the nation.