Are we doing ourselves any favors repeating this 90% number?

[Progressive dog]

96. If I have to sell a car, it doesn't turn me into a car dealer

Gun owners are not the same as gun dealers. Most of those 80 million gun owners are not furiously buying and selling guns. You have to explain why you are allowed to make up things like that and why your poorly informed beliefs should be treated as fact.
When we talk about guns for protection, you do know that gun owners or their family members are much more likely to be injured than protected by the guns.
Let me repeat the only explanations needed.
This is a democratic republic. The majority should decide laws within the limits of the constitution. The majority want universal background checks to become law. If most Republicans along with a few democrats continue to obstruct, some of them will be harmed politically. Gun nuts get the same vote that I do. The 4 million NRA members, most of whom claim not to have your extremist view, don't come near a majority of gun owners.
I am not answerable to you or the NRA as to my reasons. You would deny that my reasons exist, continuing to confuse your opinion with fact. I do not expect to convince gun nuts.
So I think of people with your views as too far removed from reality to reason with. It's kind of like triage where you are one that can't be helped.