About an hour into last night’s Republican debate, Ohio Governor John Kasich excoriated Donald Trump’s mass-deportation plan, calling the idea that we might deport 11 million undocumented immigrants “not an adult argument.” We have to do it,” Trump replied. “We have to.” But how would he do it? Once he had removed the immigrants from their homes, would he put them in camps while he determined their countries of origin? Or would he just deport them all—Guatemalans, Uighur Chinese, Nigerians, French—to Mexico? Will the deported immigrants fly commercial, or will there be some kind of train? These are the questions no one asked at the fourth GOP debate, while we waited for a real candidate to take the stage. But this is it. These vague, impossible ideas are not ciphers for real policy different Republicans will tell us about later. There is no one behind the curtain.