Prominent political observers in Latin America, the Wall Street Journal reports, are getting a tad nervous about Donald Trump. That’s not because President Trump would send their ex-pats back home. It’s because they know the type all too well. Mr. Trump incarnates the caudillo in the style of Juan Peron or Hugo Chavez: vulgar, clownish, vain, menacing, populist, authoritarian. And yes, some of those characters have had their own radio and tv reality shows.

It’s worth paying attention. A perfectly plausible theory holds that presidential systems have a tendency to produce such “leaders.” What’s spared the U.S. from that fate is our moderate two-party system—which appears to have come to an end.

A very fine recent article by Javier Corrales, “Autocratic Legalism in Venezuela,” describes that unfortunate country’s slide into autocracy. For the most part, the author explains, the rise of an autocratic executive was accomplished through and under law:

[T]he autocratic aspect of these laws is not always overt. It is often buried among an array of clauses or articles that empower citizens or other political groups, and these surrounding clauses encourage empowered groups to support these laws, at least initially. But there is always one clause that ends up empowering the executive branch far more than other actors …  [Moreover], these laws have been enacted in a constitutional manner, at least insofar as they have been duly approved by constitutionally sanctioned processes. This paradox poses a twofold problem for the opposition: 1) Such laws bolster the state’s capacity to control nonstate actors, and 2) they cannot be easily challenged because they have emerged through constitutional channels.

And “once sufficient domestic institutions are established to permit the state to govern in authoritarian ways, these institutions become the preferred instruments for making policy choices.” In short, it’s hard to reverse course.

I get it: the United States has democratic traditions and defenses Venezuela didn’t have, etc. But there’s quite a bit to worry about here.