He also said he was going to ensure that folks that shouldn't have guns won't be able to get them. Sounds great but how we gonna go about doing that without trampling on the rights of the law abiding?
Even more important, they need to implement some way to back out a mistaken entry, because mistakes do happen. With their lazy-as methods, once someone is put on the NICS list (or whatever), they are SOL indefinitely.
Basically, SCOTUS unanimously (including the n00bs) allows gov't agencies to interpret their own rules, and gives those interpretations deference.
(Technically, Chevron deals with agency determinations of statutes, rather than the agency's own rules. But, despite what appeared to be divisions among the justices at the oral argument for this case, the ultimate decision was 9-0 supporting federal agencies.)