Like I've said a number of times, that's a loser right out of the gate. When are we going to stop being on the defensive responding to questions carefully framed in the tradition of "When did you stop abusing your wife?"
The right response is "Who the hell are you to tell me what I need or don't need? How about we go over to your house and I'll tell YOU what you don't need and take it off your hands, okay? " Or, like this guy said "This is just a political appeal to the ignorant." The chances of logically convincing someone who now thinks otherwise that 30 round mags and "assault rifles" should remain legal are zero.
When anyone asks why I NEED something they cannot understand I point out that Marx also was concerned with defining the needs of the people. When you are told what your needs are from a government, you are a slave. You only NEED to live in a cramped apartment sharing a bathroom and kitchen with another family, fed on gruel and a nice floor mat to sleep on and a bicycle to go to work.