A flock of Ice agents, some masked, some sporting military-operator fashion for show, smooshed the New York City comptroller, Brad Lander, up against a wall and handcuffed him in the hallway of a federal courthouse in early June, shuffling the mild-mannered politician into an elevator like the Sandman hustling an act off the stage 10 miles north at Harlem’s Apollo Theater. Like at the Apollo, Lander’s arrest was a show. News reporters and…