I'm going to start this out by saying I'm not an attorney. Also, I would prefer no restrictions on gun ownership but until the current laws are changed or struck down by SCOTUS then we have them on the books.
There were two critical issues I saw in the clip (I think Haz should be OK with my usage of clip in this case). If federal law makes it illegal for private sellers to sell a gun to those who they have reason to suspect could not pass a background check then 19 people at these gun shows should have been held accountable in some form or another. The second is the issue of what criteria defines a business with regard to selling guns. I have no clue from the clip but it suggests that selling 348 guns constitutes a gun business. I don't know.
It looks to me that if the Feds want to clamp down on the so called "loophole" they could get a former felon and have a highly publicized sting operation. Have the guy go around like the one in the clip and suggest that he can’t pass a background check. If the seller sells him a gun without a background check the seller gets busted when the money changes hands.
It seems they could do that under existing law without new legislation. Once they get someone on the sting they could investigate if the seller is a business.
Enforcement of existing law could go a long way to encourage dealers on the fringe into voluntary enforcement. I would rather have existing law enforced rather than have new laws imposed.