“Zayd Dohrn still vividly remembers the most striking moment of his childhood. ‘Coming down the stairs in our fifth-floor walk-up in Harlem,’ he told me from his living room in Chicago, ‘seeing these two guys leaning on a car, and knowing right away that they were federal agents.’ His parents, on the run from the FBI, had schooled him on telltale signs that they were being watched. ‘It had a nightmare quality,’ the 44-year-old playwright and Northwestern University professor said. ‘Definitely a moment of realizing your life is going to change, and realizing that all the things you’d been worried about or been thinking about as a kid were actually happening.’ Dohrn is the son of Bernardine Dohrn and Bill Ayers, two of the most notorious, mediagenic leaders of a radical wing of the late ’60s New Left: the Weather Underground. In Mother Country Radicals, his new podcast with…