I wonder what, specifically, they would have someone do???
Something.
Devil is in the details. Nobody knows what to do, or what specific legislation can pass Congress, etc.
they could do all the background check and red flag laws and limit ammunition sales and other things, and you would still have demented individuals who would carry out attacks.
People sometimes point to Britain as having such a small number of gun crimes, but they have acid attacks and knife crime which kills people.