You know what finally got them super-chatty? Discussing the FBI, the CIA, United Fruit in Guatemala, Fidel Castro, etc. As a group, they lean left. They talked about how the American government is sometimes hypocritical and (get this) how United Fruit was like it's own "little colonial power" (one of my students' quote!). I could barely get in a word--or a question--edgewise.
They also liked discussing student movements in the 60s--no surprise there--especially SNCC and the SSOC. They had a big debate over SNCC's politics--particularly the expulsion of white members and the conflict between men and women. One of my students asked if I thought Stokely Carmichael's positions on the role of women and white involvement in the movement led to SNCC's demise.
So, in the last few weeks, I've finally gotten the participation I longed for.