Sometimes I agree that I'd agree with acomplete ban on all firearms, and then ask them how they could ascertain there was not a single firearm left in the world.
Well, I had to join the board to respond to this one, especially since you're a neighbor (Woodbridge, VA here....)
I realize that this is all hypothetical speaking, but I think you've hit on what I think is the stupidest anti argument out there. I'm sure that they think that the end goal is to be completely rid of all firearms and thus completely rid of firearms violence.
Suppose we do that. We actually go door-to-door and confiscate, we actually imprison or otherwise deal harshly with people who hold back. What's the end result?
How long after that will taxes go up to 90% of all income? How long before police run roughshod over the population? How long before you're told what your job is going to be, how many kids you're going to have, what churches you're allowed to attend, and what houses you're allowed to live in, all in the name of "equality"?
Less than a lifetime. Probably much less. It's human nature that some people seek domination over other people.
It happened in the recent past, it still happens to this day, and it'll continue to happen everywhere the people don't have the right to defend themselves. I'm fortunate enough to work with a former member of the USSR army - the USSR wasn't that long ago - so I get periodic reminders of what things could be like.
And when they say "it could never be like that in America", I usually respond by pointing out that we still have our guns and yet the federal government still figured out how to regulate how much we can poop in a single sitting.