Father Daniel Berrigan, a...

...Jesuit priest and high-profile member of the New Left in the 1960s, died at age 94.

From his obit in the New York Times:

He also had a way of popping up in the wider culture: as the “radical priest” in Paul Simon’s song “Me and Julio Down by the Schoolyard”...

I'm not sure if I knew that or not.