As our newspapers and TV screens overflow with choleric attacks by President Trump on the media, immigrants, and anyone who criticizes him, it makes us wonder: What would it be like if nothing restrained him from his obvious wish to silence, deport, or jail such enemies? For a chilling answer, we need only roll back the clock one hundred years, to the moment when the United States entered not just a world war, but a three-year period of unparalleled censorship, mass imprisonment, and anti-immigrant terror.