Where to Begin...?

Question sent via Facebook messenger in re "Situational Obliviousness or Happy Coincidence?":

I am a constituent of Bruce Franks, Jr in St Louis. He visits my cafe frequently. If I were to bend his ear about the flaws of that 72 hr bill, what would you recommend I point out to be the most persuasive in 5 minutes?

I suppose you could point out how such a system would be useless without registration, and without requiring each gun owner to keep an inventory by serial number, or you could point out how they could end up incriminating themselves if it turns out the gun in their possession was not obtained through an FFL, or how if they're "prohibited persons" themselves, requiring them to self-report their possession is a violation of their Fifth Amendment right. So right off the bat, criminal constituents are exempted.

Innocent victims could also end up digging out of an expensive legal hole if the gun they report later turns up at a crime scene, and conversely, perpetrators could abuse such a reporting system to have it on file they reported their weapon stolen.

What if you don't check your guns daily, and it's been gone for longer than 72 hours? Which cities have already enacted such edicts and not even used them to prevent, solve or prosecute one crime? Ask him who else has already tried it and what their success rate has been, and don't let him get away with dancing around with a non-answer.

And noting the best legal advice available, don't talk to the police, why would Franks require his constituents to do so, especially without a lawyer?  Can they all afford one?

You could point out all of this and no doubt more, but I might be inclined to just ask one question of him or of any politician proposing this:

Where do you get your constitutional authority to require this of the citizenry?

Then insist on an immediate and specific answer.

[Via David H]