If, as now seems possible, Democrats dominate the 2018 and 2020 elections, and they end up governing as unilaterally as the Republicans have, Brown fears that “a cycle will be created, in which one side pushes as far as it can until it’s thrown out, then the next one does it, and then it will happen again.” He compared it to a car “fishtailing”: “I was driving on the freeway, I don’t know how fast, and I almost missed the exit, and made a hard right onto the ramp. Luckily, I got control back. But it’s that kind of perturbation of a system. So,” he resumed, “the Democrats get more extreme, the Republicans get more extreme, and you have an ungovernable America. And a stop-start, not-reliable superpower. Other people will have to react to that level of uncertainty, and that will not be positive for America’s role in the world.

“Therefore, it’s very important to take prudential steps to keep a stable society. I’ve always thought that’s important—to keep balance. Don’t push things too far, because it will unnerve people.”

During the past year, Brown has been reading about the Weimar Republic. He noted certain similarities between Germany in the thirties and the United States today—in particular, “the erosion of familiar cultural foundations. The world is changing quite a lot, and that can undermine people’s sense of confidence.” He was reflecting on this last fall, when he spoke at several climate conferences in Europe. The Weimar period “was quite a wild time in Germany—very expressive, very artistic—but it all turned out bad,” he told me. “When I was over in Baden-Württemberg, I gave my speech, and after I finished a young man and a young woman got up and they played a beautiful flute song, highly civilized. But they were very civilized before. I’m trying to say, things change. Stuff happens. Somehow, I don’t feel confident that, just because it looks good, it can’t get worse.”