Let me say right here that I don’t for a moment think the United States will follow the path of Venezuela, Germany or Italy. Yes, I do see in Trump these authoritarian tendencies — plus a troubling fondness for other authoritarians, like Vladimir Putin in Russia and Rodrigo Duterte in the Philippines — but I’m confident our institutions are stronger than Trump.

It’s true that he has tried to undermine institutions and referees of our political system: judges, the Justice Department, law enforcement agencies like the F.B.I., the intelligence community, the news media, the opposition party and Congress. But to his great frustration, American institutions have mostly passed the stress test with flying colors.

“President Trump followed the electoral authoritarian script during his first year,” Levitsky and Ziblatt conclude. “He made efforts to capture the referees, sideline the key players who might halt him, and tilt the playing field. But the president has talked more than he has acted, and his most notorious threats have not been realized. … Little actual backsliding occurred in 2017.”

That seems right to me: The system worked.

And yet.

For all my confidence that our institutions will trump Trump, the chipping away at the integrity of our institutions and norms does worry me. Levitsky and Ziblatt warn of the unraveling of democratic norms — norms such as treating the other side as rivals rather than as enemies, condemning violence and bigotry, and so on. This unraveling was underway long before Trump (Newt Gingrich nudged it along in the 1990s), but Trump accelerated it.

It matters when Trump denounces the “deep state Justice Department,” calls Hillary Clinton a “criminal” and urges “jail” for Huma Abedin, denounces journalists as the “enemy of the American people” and promises to pay the legal fees of supporters who “beat the crap” out of protesters. With such bombast, Trump is beating the crap out of American norms.

I asked the authors how we citizens can most effectively resist an authoritarian president. The answer, they said, is not for Trump opponents to demonize the other side or to adopt scorched-earth tactics, for this can result in “a death spiral in which rule-breaking becomes pandemic.” It’s also not terribly effective, as we’ve seen in Venezuela.

Rather, they suggested protesting vigorously — but above all, in defense of rights and institutions, not just against the ruler. They emphasized that it’s critical to build coalitions, even if that means making painful compromises, so that protests are very broadly based.

“If these actions are limited to blue-state progressives, the risk of failure and/or deeper polarization is very high,” Levitsky told me in an interview. “Extraordinary measures are sometimes necessary to defend democracy, but they should rest on extraordinary coalitions — coalitions that include business leaders, religious leaders and crucially, as many conservatives and Republicans as possible.”