I have no respect for anyone who would propose to violate the US Constitution. In many cases, I will agree that the Constitution is vague enough to allow for proposals I disagree with.
But I have yet to meet an anti-gun activist who can answer this one question satisfactorily:
Regardless of how I feel about your proposal working to stop crime or make anyone safer, the US Constitution says that the right to keep and bear arms shall not be infringed. Webster's dictionary defines infringe as to encroach upon in a way that violates law or the rights of another. It also lists as an obsolete definition that it meant to frustrate or defeat. Since I do not like to use the word or phrase I am defining in the definition, we can take either of the obsolete definitions. Can you explain how your proposal is not an attempt to frustrate or defeat the rights of a citizen to keep and bear arms?
The most common answer is that no right is absolute, which I agree and disagree with and can show them why this right is as absolute as it gets. I also get that something like registration is not an infringement because it isn't stopping them from doing it. That is also easily answered as yes, it is because it stops him from his right if he does not register.
If they were honest, all it takes is to admit they want to change the Constitution. Short of that, they are all liars trying to control people.