> Best case, they can try to limit the sales of assault weapons (though there is no definition of that) and closing the insane loopholes that mean no-one needs a background check if they buy a gun at at a gun show, etc.
The problem with both of these proposals is that they're ridiculous.
Around 95% of shootings in the US are with handguns. Prohibiting some rifles based on cosmetic characteristics is not useful. (But still very irritating since they're quite popular with non-murderers.)
The "gun show loophole" has nothing to do with gun shows. Anyone in the business of selling firearms is required to do a background check. What it's referring to is that a private person can e.g. sell a rifle to a hunting buddy without a background check. Which keeps coming up because the statistics make it easy to mislead people.
A significant percentage of firearm transfers end up not requiring a background check because they're private, but it's because there are so many transfers between friends and family, not because there are so many criminals buying firearms at gun shows.
The problem is fundamentally this. Most of the people who commit the mass shootings that make the news would actually pass the background check. The people who don't pass are the drug dealers but the drug dealers get their guns the same way they get their drugs.
Canada has a lot of guns but very few homicides. Mexico has strict gun restrictions and twice the firearm-related homicides per capita as the US. The solution isn't gun laws.