The President and Congress both derive their authority from the Constitution, not the other way around, no matter what they think. The Constitution derives its authority from The People, despite statements to the contrary from Washington, DC. The 9th and 10th Amendments clearly state that any right not assigned is retained by The People, but we would be asking the usurpers to agree that they have no right to regulate arms.
Never try to educate someone who resists knowledge at all costs.
But what do I know?