
“If Voting Changed Anything They'd Abolish It”
Title of his autobiography (1987)
A variant of a slightly earlier quote: "If voting could change anything, it would be illegal" ( 1978 https://books.google.com/books?id=RPgcAQAAMAAJ&q=%22if+voting+could+change+anything%22&dq=%22if+voting+could+change+anything%22&hl=en&sa=X&ved=0ahUKEwjg4IDksJHMAhVPxWMKHc7sBikQ6AEIJTAC)
Variant: If voting changed anything, they'd abolish it.