@F4Gary stated that the POTUS put mandates over ALL federal employees (including military) with the exception of Congress and the USPS.
@PopsNole stated POTUS didn't have authority over Congress and you were unsure about the USPS.
Now you are stating Congress always is treated differently and further suggesting that Congress has the authority to override Presidential Executive Order (which this was, not a law which went through the proper channels).
Did I miss something Pops? If so, I apologize.
GO NOLES!!!