There are almost as many definitions of the term "progressive" as there are letters in the word.

As one writer for the BBC put it, "A progressive is someone who wants to see more economic and social equality - and hopes to see more gains in feminism and gay rights. They're also supportive of social programmes directed by the state - and they'd like social movements to have more power in the US."

They're different from traditional American "liberals" in that they tend to favor putting more of the power of government to work to ensure that large, powerful, private sector organizations and institutions play by rules that support progressive goals.

In healthcare, for example, traditional "liberals" would favor using government funds to buy drugs for the poor. "Progressives" would favor that, but would also insist that price regulations be imposed on big Pharma and Medicare's bulk buying power be used to drive down prices as well. Obamacare, had it Medicare-for-all, would have constituted a classic "progressive" solution to an almost universally acknowledged problem.

Conservative rhetoric aimed at "progressives" is often couched in the language of a debate about different "means" to achieve the same or similar "ends." Preaching the "advantages" of letting unregulated market forces drive drug prices is a classic example

The Trumpist "base", however, differs radically from traditional conservatism.

Trump and a disproportionate number of those who are die-hard supporters, simply don't like or don't care what happens to the people and institutions "liberal" and "progressive" policies are designed to help or protect.

Hence Trump's rhetoric.

And hence, while not all Trump supporters are foul-mouthed, ill-mannered, or racist, homophobic, misogynists, or Chauvinistic; while not all are neo-Nazis, anti-Semites; antigay, anti-Muslim, anti-Hispanic, anti-science, anti-press, anti-academic, and worse . . . those who share one or more of those attitudes flock to the Trump cause.

Why? Because he speaks their language and, in doing so, frees them to do the same.

Obama and Hillary Clinton, immigrants and refugees, "regulations" and the "mainstream media" are classic symbols of everything such people despise.

Trump plays on fear and prejudice and, in doing so, rallies the worst of us.

John McCain summed up the phenomenon at work in foreign affairs well.

"To fear the world we have organized and led for three-quarters of a century, to abandon the ideals we have advanced around the globe, to refuse the obligations of international leadership and our duty to remain 'the last best hope of earth' for the sake of some half-baked, spurious nationalism cooked up by people who would rather find scapegoats than solve problems is as unpatriotic as an attachment to any other tired dogma of the past that Americans consigned to the ash heap of history."