Federal public employees are paid with federal tax dollars and work for We the People. We pay their wages. Which by the way is true for the entire federal government, including the President. Whether elected or appointed, they work for us, not the other way around. It seems that many have conveniently forgotten this fact.
State public employees are paid with tax dollars collected in the state and work for the citizens of the respective state.
Since all public employees work for us they must answer all questions asked of them or be terminated.