was intended to be a 'poison pill' for the whole bill (the Gun Onwer Protection act), and (as noted) was passed at the last minute, by voice vote only.
Reagan drew a lot of heat since then for signing it into law, but at the time, it was considered the breatest good for the greatest number. AND IT WAS.
Lots of us would love to be able to own new FA firearms, and have them added to the registry. Some are quite upset that they can't, and rail against Reagan's signing the bill. But the reality is that a good many people have been saved from a lot of trouble by the law, and overall it did more good than harm.
The way to get around this, is not to have an open public debate, and try to generate support for easing the FA ban, that will not work. Decades of propaganda (and there's really no other word for it) in popular entertainment showing only criminals (and govt emplyees-police/soldiers) with FA guns has done its work on the American public.
I say the way to fix the situation is to have some pro gun legislator, quietly, without fuss or fanfare, slip a line into a "must pass" bill, reading something like "change line xxxx, law abcd, to read.....," and just shut up about it if it passes. Then, after it is established law, then just follow the law, as it exists, the same way we do now.
Once that happens, when the antis figure out what happened and start screaming about how "anyone can buy a machine gun", we make sure the focus of the info (as best we can, anyway) is to point out that the Fed background check and (as importantly) permission from the head of local
law enforcement is needed to buy one. Since the only people who can buy are already approved by both the Federal govt AND the local cops, how can they disapprove? If those approved people aren't trustworthy enough, neither are govt employees (in and out of uniform), who seldom have anywhere near the same amount of scrutiny done on them, before the govt hands them an automatic weapon.
Might not work, but why not try?