For limited durations, in isolated contexts, it’s a party. On a Thursday morning the number of protesters outside the brutalist building from which ICE conducts its menace in Minneapolis swells from 25 to at least 100 by early afternoon. Spirits are high. At times there is topical music (“Fortunate Son”; Ray Charles’s “America the Beautiful”); now and then someone will dance in the street. There is a dog in booties wearing a serape, led around by a man in a cape with a cardboard sign that reads SHAME. There is a quiet clown and a loud man in a wide-brimmed...