I think we are dancing about, and ignoring the critical part of the discussion. Its not about whether background checks work, or if they are, or are not a good thing. It is about whether the govt has the legal authority to compel us all to use them. Certainly they can compel us, by passing a law, and enforcing it, but do they have the right to do it?
See this trend in other areas of our lives. Just because something is a good idea, and might have benefits for us as individuals, or for society in general, is it our govt's place to compel us to do it by force of law? And is it their right in general, or just for guns, and some other specific things, because they are "dangerous"?
Wearing seatbelts is a good idea. Wearing a motorcycle helmet is a good idea. Having healthing insureance is a good idea. And we got along fairly well, I think, for generations with these good ideas. But today, it is the LAW that you MUST do or have this. And if you do not, even though there is no injury, you get punished by the govt for not having it. IS that right?
Along the same line of thinking are the proposals (and in some places laws) requiring you to have your guns locked up in your home. Sure, its a fine idea, but who benefits from it when you get caught not doing it? Only the govt.
I am up to my eyeballs in studies that say this, or that, is good, or bad for us. And I am fed up even further with laws and regulations based on "studies" touting the "cost" of not doing it, what ever issue is under discussion.
We are being forced to go to the nth degree in so many things, to be safe, from ourselves, and to reduce the "cost" of ..whatever to society, by LAW. It seems that the concept of both individual responsibility in committing an act, (or not committing an act) and the responsibility for paying for that act appears to be an outmoded and no longer relevant concept. It is, but I don't think it ought to be.
And I resent the laws that give the govt the legal right to pick my pocket, when no harm has befallen, simply in the name of safety for the masses.
And worst of all is the excuse that we "need" such things. It's not just a slippery slope anymore, its a vertical cliff. Studies, like surveys can be rigged to deliver any preconcieved result.
There is a "study" that claims that 99%+ of all criminals ate bread, or a bread product within 30 days of commiting the crimes. Yet, at this time, no one is screaming we need to ban bread, or pass a background check to buy a loaf.
after all, if it saves just one sandwich......
All else being equal (and it almost never is) bigger bullets tend to work better.