“The Trump era could last another thirty years.” That was the headline last week on a widely discussed column by Gideon Rachman, principal foreign affairs commentator of the Financial Times. In the three years since Brexit and Trump, Rachman observed, a global populist movement has gathered momentum: Jair Bolsonaro in Brazil, Victor Orban in Hungary, Matteo Salvini in Italy, not to mention Xi Jinping in China, Vladimir Putin in Russia, and Recep Tayyip Erdogan in Turkey. The bad news, he wrote, is that such movements tend to last around thirty years. Rachman was right about the cycle, I thought, wrong…