This is unbelievably heartbreaking. That poor kid.
How long will the U.S. let this go on?
It will last as long as the US
people let this go on. Reelecting the same corrupt politicians and most US citizens doing nothing more than complain about it. Right now, there's not a 3 millions+ crowd of angry protesters demanding reforms sitting in front of the capitol. So those politicians can ignore you, because you, the US population as a whole, don't really want gun control all that much, right?.
Historically speaking, the only thing that pushed one state to adopt vigorous gun control was, guess it... the Black Panther movement (where armed vigilantes teams started following cop patrols to make sure they kept their racism on a tight leash) and black people starting to arm themselves en-masse. Suddenly open-carry and assault rifles got outlawed. Wonder why...
The only other thing that could convince those politicians to really embrace gun control, would be for them to be directly and repeatedly targeted. After all, money only matter as long as you keep breathing. But as long as it happens to someone else, the status quo is fine for them.