from Stanford University in 1941, where he had been part of the Army Reserve Officers' Training Corps.

Less than a month after the attack, Marks reported to Fort Ord as a second lieutenant in the United States Army.

Serving in the Pacific Theater of Operations, including the Philippines Campaign (1944–45), he was the Assistant Defense Counsel for the Court of the Eighth United States Army during the Occupation of Japan.

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.

While still a Republican, Marks made an unsuccessful run for Congress in 1982 to unseat Phil Burton, losing by a margin of 58%-40%.