 Marks first ran unsuccessfully for the State Assembly in 1954 as a Republican.He was elected in 1958 as a Republican to the Assembly, serving until 1966, when he was named a city judge.When a vacancy occurred in a State Senate seat in 1967, he ran in and won the special election as a Republican, defeating Democrat Assemblyman John L. Burton, who was the younger brother of powerful Democratic Congressman Phil Burton, head of the San Francisco political machine.