It's about keeping all guns away from certain people, and it's the people that, it turns out, we all agree shouldn't have guns: convicted violent criminals, domestic abusers, the dangerously mentally ill.
Significa tirar todas as armas  de algumas pessoas, que são as pessoas que todos concordam que não deveriam ter armas: criminosos violentos condenados, agressores domésticos e doentes mentais perigosos.