Elsewhere, progressives have called for forcibly disbanding the National Rifle Association, freedom of association be damned. Democrats elsewhere have called for designating the NRA a “terrorist organization.” Democrats in New York have abused the power they have over the financial-services industry to try to shut down the rival political organization through backdoor means.

Others have called for gutting the Bill of Rights and trampling on due process, empowering government to curtail, suspend, or revoke the civil rights of Americans who have not been arrested or charged with any crime, much less convicted of one.

To the German political theorist Karl Loewenstein we owe the term streitbare Demokratie, or “militant democracy,” the principle that liberal democratic governments must sometimes employ illiberal and undemocratic means to fight nascent totalitarian movements. This is the theory under which Germany bans certain political parties (both neo-Nazi parties and some Communist parties) while countries such as Austria can hand down lengthy prison sentences for selling forbidden political books. The United States historically has not countenanced such invasions, and classical liberalism is embedded in our Constitution through the Bill of Rights — which is, it is important to understand, a check on democracy, putting certain principles beyond referendum. The American model has targeted such organizations as the Ku Klux Klan and the Weather Underground not as ideological offenders but as organizations engaged in criminal conspiracies independent of their political views, however repugnant those views may be. But the American Left (and, to a lesser extent, certain populist constituents of the Right) has abandoned that liberalism and looks partly to Western Europe for other models.