“When guns are outlawed, only outlaws will have guns.”
[...]
could be transformed into an argument like “Since it’s
possible to get guns illegally with some effort, and
criminals need guns to commit their crimes and are
comfortable with breaking laws, it might only slightly
decrease the number of guns available to criminals. And
it might greatly decrease the number of guns available to
law-abiding people hoping to defend themselves. So the
cost of people not being able to defend themselves might
be greater than the benefit of fewer criminals being able
to commit crimes.”
I think the one-line quote would persuade people more readily than the 10-line quote.