But populist presidents and prime ministers, on average, stay in office twice as long as nonpopulist ones: six and a half years compared with three.

As Jordan Kyle and I have shown, this discrepancy becomes especially striking when you examine governments that have been in office for more than 10 years. A populist president or prime minister is five times as likely to remain in office after a decade as a nonpopulist one.

We also found few examples of populists who lost power after just one term. As countries such as Hungary and Turkey demonstrate, voters tend not to recognize their mistake until populist leaders have done serious damage to democratic institutions.

As we approach an election in which democracy is on the ballot in the United States, the enduring popularity of populists elsewhere should serve as an urgent warning.