Conversation so far:
what did Leonard Bernstein have to do with social activism?
Bernstein would go on to fight for everything from the influences of "American Music" to the disarming of western nuclear weapons.
Are there any other interesting aspects about this article?
He was blacklisted by the US State Department and CBS in the early 1950s.
what was he blacklisted for?
Bernstein had been involved in various left wing causes.

Question: are there examples of any?
Self-contained rewrite: are there examples of Leonard Bernstein's involvement in left wing causes?