In September, Pope Francis will visit the United States for the very first time. His trip is guaranteed to be interesting, partly because this pope often does and says unpredictable things to great effect, and partly because his teachings don’t map neatly onto the American left-right political spectrum. As the Washington Post columnist Michael Gerson said at a panel at the Aspen Ideas Festival on Friday, “This is someone who is ambivalent about America—this is the mothership of global capitalism.” It will be fascinating to watch what happens when he addresses Congress, for example: Which legislators will clap when he talks about climate change?