I don't have any idea as to why the average American gun supporter can't come to terms with the following;
A mass shooting is made possible by the shooter having access to a semi-automatic assault rifle. That is a rifle firing multiple bullets per second. That equals multiple deaths per second if used properly, which they have been more times than you can probably count in the last year never mind the last 40.
Take away the assault rifles and someone who is inclined for whatever reason to commit mass murder, can only do so using a melee weapon (knife, hammer, baseball bat etc). Someone in the process of committing mass murder with one of these can be far more easily escaped or apprehended and much sooner. Don't get me wrong, someone using a knife to attack people is not ideal, but that person is going to kill infinitely less people than a so called bully victim turned soldier with an assault rifle. Why can't you see that? take away assault weapons and you literally save hundreds of thousands of lives, if not millions in America. School-age people no less.
Look at the London bridge attack of 2017, 8 people killed by three attackers who rammed pedestrians on the bridge and then got out of the vehicle and began attacking people with knives in the centre of London. What if they had assault rifles? All three of them? Exactly. It's beyond belief what that scene could have looked like. and it's even further beyond belief that there are still Americans supporting gun rights in America, after thousands & thousands of deaths in the last year alone!
The first page alone has 24 separate incidents from yesterday 3rd August. Astonishing! Greatest country on Earth? Not yesterday it wasn't.
https://www.gunviolencearchive.org/reports/number-of-gun-deaths
There are some laws where loopholes could be closed, others are slippery slopes that could be exploited politically.
But the fact remains criminals do not abide by laws, and someone mentally hellbent on killing will find a way. This one didn't use a gun.
Cure the cause not the symptoms.
https://en.m.wikipedia.org/wiki/Timothy_McVeigh