>It's written into our constitution

To an extent it is, but the 2A reads:

>A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

​

Now, some people will say that anyone over 18 is part of the militia so it's all honky dory, but I think that's really overlooking the 'well regulated' part. What could a well regulated militia look like?

It would need uniforms, a leadership structure, bylaws, regular training, some kind of funding, a muster point, etc. A well-regulated militia might refuse membership to someone convicted of domestic violence, or using hate speech, or who has signs of being a mass shooter. A well-regulated militia might store firearms and ammunition in a safe area so that they're available for training or when a foreign army invades.