Bernie Sanders campaigned for the Socialist Workers Party in the 1980 and 1984 presidential campaigns and was investigated by the FBI for his ties to the Marxist group. Sanders has always played down the extent of his involvement with the party, which included radicals who praised the Soviet Union and Cuban communists, and has denied ever being a member. Asked in 1988 about his role as an SWP elector in 1980, he said: "I was asked to put my name on the ballot and I did, that’s true." In fact, his ties to the party are deep and enduring. The...