One of the excellent sources from the Baude article to which last post linked approvingly is a recent Tenth Circuit case, Wyoming ex rel. Crank v. United States. At issue was Wyoming’s attempt to do an end-run around 18 U.S.C. 922(g)(9), a law prohibiting anybody convicted of a state, federal or tribal domestic assault misdemeanor from owning a gun that has traveled in interstate commerce.* Wyoming sought to advance its gun rights policy (it likes gun rights) by taking advantage of an exception in the law — if the misdemeanor conviction has been “expunged or set aside” then it does not operate to bar the ownership of any gun. 18 U.S.C. 921(a)(33)(B)(ii). Accordingly, Wyoming passed a law expunging state misdemeanor convictions but only “for purposes of restoring any firearm rights lost.” (The law, Wyo. Stat. Ann. § 7-13-1501, has since had the “for purposes” modifier deleted.)
The Tenth Circuit held that the Wyoming “expungements” did not operate to remove domestic assault misdemeanants from 18 U.S.C. 922(g)(9)’s prohibition. It interpreted the language of 18 U.S.C 921(a)(33)(B)(ii) — the provision providing that those whose domestic assault convictions are expunged are not deprived of firearm rights by 18 U.S.C. 922(g)(9) — as applying only to expungements that “completely remove the effects of the conviction in question.” Wyoming ex rel. Crank v. United States, 539 F.3d 1236, 1245 (10th Cir. 2010). Because the Wyoming law only partially, for purposes of the restoration of firearms rights, removed the effects of a Wyoming domestic assault misdemeanor conviction, the court held that expungements pursuant to it were not expungements for purposes of federal firearms law.
Baude points out that this is a rare example of a state trying to control federal law by taking advantage of the fact that great swathes of federal law rely on state law (tax law uses state definitions of marriage (and death), criminal law uses state convictions, etc.) It is efficient, and also serves valuable substantive policies, for federal law to rely on state law (as opposed to, for example, developing its own marriage law and apparatus for administering it). But such reliance is ineffective if states manipulate their laws in order to surreptitiously work changes in federal policy.
* The “traveled in interstate commerce” requirement — an “interstate hook” — is necessary in the wake of United States v. Lopez‘s striking down a law prohibiting the possession in a school zone of any gun, whether or not it had traveled in interstate commerce, because such possession, even though purely intrastate, “substantially affects” interstate commerce.