Once again.....
Truman orders loyalty checks of federal employees
"In response to public fears and Congressional investigations into communism in the United States, President Harry S. Truman issues an executive decree establishing a sweeping loyalty investigation of federal employees..."
https://www.history.com/this-day-in-history/truman-orders-loyalty-checks-of-federal-employees
So it's been a long long time. That was a very disturbing thing as well BUT - it wasn't loyalty to TRUMAN, was it?
Trump is demanding loyalty to him.
Truman's loyalty check order was mainly to root out communists. But an employee who is not loyal to the President is a security risk.
President Eisenhower changed Truman's order to include other security risks:
"Previously, the criteria used to define a security risk were largely political, that is, affiliation with suspect organizations or a clear demonstration of disloyalty. Executive Order 10450 added more general estimations of character, stability, and reliability. Its language was broad: "Any criminal, infamous, dishonest, immoral, or notoriously disgraceful conduct, habitual use of intoxicants to excess, drug addiction, or sexual perversion." At the same time, the executive order's provisions contained advice on evaluating character problems, as in its provision that the medical valuation of a psychological problem should show "due regard to the transient or continuing effect of the illness."
Executive Order 10450 - Wikipedia