"You cannot negotiate with people who say what's mine is mine and what's yours is negotiable." - John F. Kennedy
I cannot verify this with an original source. The only find I made in the John F. Kennedy Library is in 1960 press releases. However, it is very difficult to read. I couldn't find the quote but the title is "The fight on crime". See http://www.jfklibrary.org/Asset-Viewer/Archives/JFKCAMP1960-1036-012.aspx#
Whoever wrote it came up with a good observation. My variant is:
A: "You owe me a hundred dollars."
B: "I owe you nothing."
A: "OK, let's compromise. You owe me fifty dollars."