So Rusty, your proposal is adding background checks for private sales? Why would that help? How many of these mass shootings would that have prevented? How many criminal injuries or deaths result from guns legally purchased in private sales without background checks?
None of these are rhetorical questions, btw - I really don't know the answers. But my suspicion is that the numbers are quite low.
Ok, and one slightly more rhetorical question: if background checks are so beneficial, how is it that these lunatics seem to keep passing them?!
I think the genie is out of the bottle on this issue, and has been ever since... the Second Amendment. The only thing I can think of that might meaningfully reduce gun crimes would be to (1) Repeal the 2A, (2) shut down all gun manufacturers in the US, (3) ban imports, and (4) engage in a massive efforts to buy back and/or confiscate and destroy guns. Even that would take decades. Since that really isn't possible, maybe we should focus on more closely tracking the mentally ill and increasing security instead.