By the time their paths first crossed in the 1960s, Barbara Deming and David McReynolds had each charted a unique course through the political and social worlds of the American left. Deming, a feminist, journalist, and political activist with an abiding belief in nonviolence, had been an out lesbian since the age of sixteen. The first openly gay man to run for president of the United States, on the Socialist Party ticket, McReynolds was also a longtime...