Laws only affect the law abiding.
Au contraire. Here's an example:
Billy Joe Jim Bob decides he's in the mood to go shoot up first graders (easy targets, large kill count). On the way he's stopped by a policeman for not signaling left. The policeman notices BJJB's AR-15 in the back seat.
Policeman: Whats with the major weaponry, Billy Joe?
BJJB: Gonna shoot rabbits.
Policeman: It ain't rabbit season.
BJJB: Aw shucks. Thanks for reminding me. Guess I'm haulin' it `round fer nuthin'.
Policeman: Well, you drive safe and don't forget to signal.
BJJB: Never happen again.
So Billy Joe Jim Bob's second amendment rights are kept safe but later 25 first graders, 2 teachers, a principal and a sheriff's deputy all die because Billy Joe had an itch that needed scratchin'.
So, what would have happened if the policeman was allowed (even required) to ask Billy Joe for his license and registration for the gun as well as the car? Billy Joe has been arrested twice for beating his wife (and kids) and can't help posting on FB about how he just wants to kill people because he hates libtards and wetbacks and was actually sent to a mental facility once for threatening people on the street for wearing the color blue. Billy Joe didn't qualify to own that AR-15. It woulda had to been confiscated and possibly he woulda had to spend a lil time in the hoosgow.
If he had gone with plan B and decided to use a chainsaw instead he might have ended up doing more harm to himself than others (what a shame).