Don’t be too confused, the NRA wrote the 1968 gun control act in its entirety.
It’s easier to collect contributions if you have something to fight.
BINGO! Thank you.
Back in 1968, the hunters of the "you don't need an assault weapon to kill deer" school were still a power in the NRA, and most people thought that there was actually a possibility of actually getting to a "reasonable" control position. Then "Handgun Control, Inc." started the "assault weapon" steamroller, and the sheepskin fell off the wolf.
The NRA of today is a different animal from back then. The "you only need a bolt-action rifle" crowd has been schooled (Jim Zumbo incident) to reality, and the "protect the Second Amendment" faction is in full control.