“In the early 1940s, James Baldwin was in his teens and living in New York City when he joined the Young People’s Socialist League, a branch of the Socialist Party of America. His first foray into formal political life followed years of informal activity, including public agitation. ‘At thirteen, I had been a convinced fellow traveler,’ Baldwin wrote in his political memoir, No Name in the Street. ‘I marched in one May Day parade, carrying banners, shouting, East Side, West Side, all around the town, We want the landlords to tear the slums down!’ Baldwin’s attraction to left-wing politics was practical, based on his experience growing up in the tenements of Harlem. ‘I didn’t know anything about Communism,’ he wrote, ‘but I knew a lot about slums.’ Baldwin’s self-conception as a budding socialist was a far cry from how he would later describe his relationship with the Left. ‘My…