"Donald J. Trump’s election has raised a question that few Americans ever imagined asking: Is our democracy in danger? Drawing on a close study of democracy’s demise in 1930s Europe, the eminent political scientist Juan J. Linz designed a “litmus test” to identify anti-democratic politicians. His indicators include a failure to reject violence unambiguously, a readiness to curtail rivals’ civil liberties, and the denial of the legitimacy of elected governments. Mr. Trump tests positive. This anti-democratic behavior continues. Mr. Trump is not the first American politician with authoritarian tendencies. But he is the first in modern American history to be elected president... because the institutional filters that we assumed would protect us from extremists, like the party nomination system and the news media, failed."