Well, I'm certainly no lawyer, so I'm not taking on Frank.
I would ask his opinion on this analysis from the Cato institute regarding a state's capacity to resist federal intervention.
Note that this link has a further link to a PDF at the bottom of the page for the whole article.
While the original premiss is about Marijuana the author makes reference to the fact that this line of reasoning may hold for other areas as well. This was written well before the current national non-discussion on gun control started.