"We need to enforce as written the laws we have." said every day in various ways.

Sure... as soon as someone does something illegal or stupid, we can "enforce a law" and arrest them or take away their 'freedom' to possess guns....if we can find them. Kinda hard to explain to their victims and their families why fools and incompetents were allowed to have guns in the first place, though.

There are 'out there' many, many people who have as their basic notion "I don't like being told what to do, and I don't trust ANY government, and I have 'moral rules' about what is 'right' and I will damn well decide for myself who needs to be shot and when!"
And as long as those people haven't done anything specifically illegal...yet, or that we can prove... they are 'allowed' to accumulate firearms of astounding power & variety. But if they go out and shoot an abortion doctor, or a politician they don't like, we'll durn sure take their guns away, and may even prosecute them--and may put them in jail..if they can't afford an expensive lawyer. Yessir... I sure feel better knowing those "laws on the books" are gonna be enforced!

Those "laws on the books" right now 'restrict' certain weapons from being modified in certain ways...but any serious person can easily learn HOW to modify them. Those laws have 'waiting periods' to buy multiple weapons...except in certain states and at certain gun shows.
   Those laws don't explain how to prevent LEGAL weapons from being sold ILLEGALLY to stupid, dangerous people, or how to prevent weapons acquired 'legally' in one state from being moved to a state where they are not legal...but boy, if we find them doing it, we'll sure 'enforce' a law or two!
In most states, it is not even a requirement to take a course in gun safety to legally buy (most) guns....and we read every day about 'accidents' to owners or their families who were NOT planning to do something 'illegal'.

The kid in Arizona yesterday had no criminal record.... he owned that gun legally.