[Talisker]

...your crystal ball is a bit clouded by cynicism. To tell a Federal District Court that the law is Unconstitutional does not, in any way, endorse the law in question. Sometimes, the best way to challenge a law is to break that law.

I'll cop to cynicism. And I'll agree that breaking a law challenges it. But effectively? There was this little disagreement in the 1860's that indicates, at least to me, how seriously the Feds take this issue. I just don't see them backing down an inch, especially when it's so easy for their courts to dismiss it as frivolous (which is exactly the legal position of the ATF at this point, and they're not just namecalling - they mean it for the technical reason I described).

[Kansas58]

Well, if they dismiss the case, that means the defendant WINS!
The prosecution generally can NOT make a habit of asking for cases to be dismissed, if the prosecution actually intends to ENFORCE a bad law.