I agree, but I'll lay you 10 to one odds that he's convicted. Whether the law is unconstitutional or not, it's the current law, and the jury must either enforce it or nullify it with an acquittal. The odds favor enforcement. I can appreciate what these guys are doing, but what sense is there in going to jail? They should be working for a CCW law in Colorado, such as we have here in Michigan. Maybe this is the opening salvo in such an attempt.
(BTW, Dan from Michigan, if you're reading this, please drop me a private reply as to an answer for this question: does Michigan's CCW permit a CCW holder to possess a handgun in Wayne County or the City of Detroit, where there are special local laws against it. I would bet that state law trumps local, but I've been wondering and I know you're up on this issue. Thanks!)
He can't challenge the law unless he is arrested and convicted, or the trial judge overturns the law, like the Federal Judge in the Emerson case did with the Lautenberg domestic violence Law. The path to protection of rights can lead through the courts as well as the legislative process.
Ever heard of Rosa Parks?