Nothing is going to happen. We could have a shooting like this every day and still the gun lunatics would not move an inch. You hear them make the same bullshit arguments about "people would just use knives, vehicles, bombs...", which is just ****ing stupid because all you have to do is look up the number of people killed worldwide by those methods every year and compare them to firearm homicides.
I grew up in house full of guns, granted they were all used for hunting, but we had a house full of guns. I still own several shotguns and long rifles. I am not that old, but when I grew up, people did not fetishize guns like they do today. If anything, way more families were gun owners because lots of people hunted back then, but people did not fetishize them. Guns were tools, tools that were used to take game. That is what they were for. We didn't shoot them for fun. They were tools, tools we were expected to take good care of. When I grew up, we kept our shotguns and rifles in the back of closets, we cleaned them before we put them up, and we never walked in the house with one before we unloaded it. This was in the 1980s and early 90s. Sometime between then and now, guns became toys for many people rather than tools.
You want to know why we have the highest homicide rate of any developed nation earth? You want to know why we see these mass shootings again and again at a far greater frequency than any other developed nation on earth?
1. We have way too many ****ing guns in this country and too many people treat them like they’re cool toys.
2. Humans are fallible creatures who when given easy access to cool deadly weapons at scale will use them to kill themselves and others.
It is that simple and until we come to terms with this as a society and quit making stupid excuses and making shitty arguments, we are going to continue to be the most dangerous fully developed nation on earth.