Gun control is a topic where it’s difficult to really boil down the totality of the debate in a bite-sized chunk. For people to follow it, they have to follow it completely for years to really get the whole view.
That’s true on both sides, to be fair. It’s easy to just assume a new gun control law will suddenly stop the bad guys, but we all know how futile that particular hope actually is. Criminals, by their very nature, break all kinds of laws. Gun control laws are just one more they’ll choose to ignore.
However, those on the gun control side who have been at this a while might argue that while gun control laws only hurt the law-abiding initially, the effects “trickle-down” to impact criminals. In other words, a total gun ban wouldn’t hurt the bad guys initially but deprived of their source of guns–the law-abiding people they’re generally stolen from in the first place–they’d eventually end up disarmed.