Voters in Sweden this month gave a leading role to a far-right party with neo-Nazi roots. Italy is also on the cusp of putting a party in power that has fascist origins. And of course, in the United States, one party has increasingly embraced election denialism and attempted to undermine the legitimacy of the electoral process.

To try to understand what, exactly, is happening, I talked with Barbara Walter, a political scientist at the University of California San Diego who studies democracies across the world. Her book “How Civil Wars Start” has become a bestseller. Rather than talk about the prospects for political violence, we discussed why many democracies are retrenching and how the U.S. stands alone — and not in a good way.

This conversation has been edited for length and clarity.

Can you walk through the vital signs of democracy that you and other political scientists have been tracking and that are trending the wrong way in the U.S. and elsewhere?

So there are probably five big data sets that measure the quality of democracy and countries around the world. They all measure democracy slightly differently. But every single one of them has shown that democracies around the world are in decline. And not just the fledgling democracies, but sacrosanct liberal democracies in Sweden, the U.K. and the United States.

These indices are like vital signs, but instead of for your body, it’s for our body politic. What are the most important ones?

So, empirically, we can’t rank order them. But we know what the good things are, and if you start attacking them, you’re attacking the vital organs.

One is constraints on executive power. You want lots of checks and balances on the executive branch. Here in the United States, you want to make sure that the legislative branch is strong and independent and willing to check presidential power. You want to know that the judicial branch is the same. Another one would be rule of law. Is the rule of law actually respected? Is it uncorrupted? You don’t want a system where certain individuals are above the law. If you want to become, say, Orban 2.0, you place loyalists in the Justice Department who are beholden to you and not to the rule of law.

You also want a free and open press, so that your citizens get high-quality information and they can make good decisions. Another one is you really want a competitive political environment, so that there’s a level playing field for people who are competing for power. You could make a very uneven playing field by party. So you can restrict the vote, you can make voting more difficult.

So these are all vital: Do you have constraints on the executive? Do you have the rule of law, so that there’s accountability? Do you have a level playing field, so that there can really be popular participation?

Another warning sign you’ve talked about is when a party becomes less about policy and more about identity, a shift one can see in the Republican Party in recent years. Can you talk about it?

The Republicans have always had a challenge that they were the party of wealthy Americans and business. The problem is wealthy Americans will always be a very small minority of Americans. So for wealthy Americans, they have to convince at least some nonwealthy Americans to support their platform. How do you do that? Well, you do it with issues of identity, their sense of threat, their sense of fear, their sense of the world is changing and “I’m being left behind.” It’s very effective.

I want to get to why we see these dynamics playing out across so many countries. You cite three dynamics. One is that the dominant caste in many nations, white people, is trending toward minority status. Another is increasing wealth concentration, where rural areas are often losing out. And then there’s a new medium that has risen that is unregulated and unmediated: social media.

On No. 3, the new medium, I would state it stronger than that. It’s not that it’s unregulated per se. It’s that it’s being driven by algorithms that selectively push out the more extreme incendiary messages.

You also wrote about another concept that I hadn’t heard before: ethnic entrepreneurs. These are politicians like, say, Slobodan Milosevic, the former Serbian strongman, who recognize an opportunity in appealing to the fears of a particular group.

Yep. He was not a nationalist. He was a straight up Communist. And again, that gets back to the difference between a political party based on ideology and one based on ethnicity. He became the leader of the Serb party.

So he saw which way the wind was blowing and he put up a sail. And that’s what an ethnic entrepreneur does?

Yes, but it can also be more strategic than that. Milosevic really had a problem in that communism was over. And if he wanted to stay in power, he was going to have to compete in elections. How is he going to get elected? And then he’s like, “Oh, like the largest ethnic group, and in this country are Serbs. I’m Serb!” If I can convince the Serbs during this time of change and insecurity and uncertainty when everyone’s a little bit on edge that unless they support a Serb, the Croats are gonna kill them, then then I can catapult myself to power. That’s classic ethnic entrepreneurship.

I want to ask you a last question I’ve been thinking about a lot myself. Like a number of news organizations, we’ve created a team devoted to covering threats to democracy. But after I read your book, I stopped referring to it as that because it occurred to me that the term threats to democracy reinforces a story that we Americans tell ourselves: that we already have a true democracy, the best darn one in the world, and we just need to protect it.

Our American democracy, even when we were happy with it and thought it was doing really well, it already had a whole series of undemocratic natures that no other healthy liberal democracy has.

Our electoral college, nobody has that. That was a compromise to rural states. We have the fact that our elections are run by partisan agents. No other healthy liberal democracy has that. Canada, this enormous country, has an independent electoral commission that runs all of the elections. Every ballot is the same no matter if you vote in Prince Edward Island or the Yukon. Or that we allow so much money to be injected into our system. Nobody else has this.

So we have not only these undemocratic features but a whole number of vulnerabilities that if you really did want to somehow cement in minority rule, you could do this legally. So in many ways we have a terrible system that’s ripe to be exploited.