Ruth Ben-Ghiat is a frequent contributor to CNN Opinion and a professor of history and Italian studies at New York University who writes about authoritarianism and propaganda. Follow her @ruthbenghiat. The opinions expressed in this commentary are solely those of the author. Read more opinion articles on CNN.

(CNN) Is America becoming a 21st-century-style authoritarian state? The impeachment hearings of the last weeks would seem to provide an easy answer: no. The very fact that such an inquiry can be held, and broadcast on national television, is a sign that our democracy is working and that our institutions are holding.

Yet the impeachment hearings also showed how degraded our political culture has become and how much progress President Donald Trump has made in implementing the authoritarian playbook that he began to write for America during his campaign.

First, the hearings revealed just how much Trump's cult of personality has tied subordinates to him, and how much of his playbook operates on keeping them in thrall to his singular threat: show loyalty, no matter what I say or do, or else.

A healthy democracy is founded on tolerance of differences of opinion, but is grounded in a shared body of norms. Autocratic governments, in contrast, need to change our opinion about what violates norms and constitutes crime and corruption.

Trump and the GOP, in de facto partnership with Fox News, are creating an alternate reality for followers in which facts are what the President needs them to be. This is a hallmark of authoritarianism.

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