As for your point about mass shootings with semi-autos, yes that can be done but I think things like magazine capacity and preventing conversions mitigate the damage. Again, I think “ban all guns” is a much easier to legislate policy from a drafting perspective, but not from a passing perspective.
Every mass shooting we’ve ever heard about was committed with a semi-automatic weapon, and conversions are already a federal felony. Magazine capacity is viable, but really nibbling at the margins. And if we’re talking about all firearm deaths instead of mass shootings, handguns are the main threat.
Clinton's assault weapons ban had a positive effect for as long as it lasted