 The Germans tried it in World War II. It didn't work really well. And in the U.S., we have always come from very different parts of the world, but we share a common political project, a common culture, a common destiny, and it's worked really well. But this idea that we want to have a country for people from that country, it's very dangerous and still part of the way we think, the way things are taught in school, that borders represent a culture. And once you cross the Canadian border, things are completely different. And once you're in the U.S., it's a different world.