You don't notice any problem with Dionne's argument? Let's look at it as reasonable people:
I think those three paragraphs are the essence of Dionne's claim, right? What's missing?
For Master Sanders, IDS Legislator:
A longer response was eaten by this lemon of a laptop I recently bought.
The short answer is that
(1) Dionne makes claims about "the gun lobby's argument", but
(2) He never quotes it.
Without the readers being able to see exactly what he's talking about -- the "gun lobby's response" -- then his characterizations of it, as "a rote response" or an "(anti)-exploitation argument", are meaningless.
As it is now, the article is worthless for understanding the post-massacre debate.