Do you think the FBI really cares who has been a member of the Communist Party when the White House and Congress is currently full of them? After the cow has bolted from the barn, there is no point closing the door.
I have a family member who had to get a security clearance. Virtually every surviving member of his high school graduating class (from the 1950’s!) was tracked down and asked by an FBI agent whether he had ever been a member of the Communist Party.
Did not ask much more than that.
So stay away from your high school’s Young Communist Club and you’re good to go with Federal employment.