They took the line that since they were the vanguard of the proletariat, their right to rule could not be legitimately questioned. Hence, opposition parties could not be permitted to exist. From 1936 onward, Communist-inspired state constitutions enshrined this concept by giving the Communist parties a "leading role" in society—a provision that was interpreted to either ban other parties altogether or force them to accept the Communists' guaranteed right to rule as a condition of being allowed to exist.