Nearly all of us had security clearances. The process of getting them involved an education in the requirements of the National Security Act. That Act makes anyone with access to classified information personally responsible for it. Whether through malice or negligence, if it escapes from his hands to uncleared hands, then regardless of his intent, he is guilty of a felony violation of federal law.
At the time, no allowances were made for political considerations. But we were honest then.