From The Federalist:

Both the District Court and the Eighth Circuit saw things differently, and by enjoining Missouri’s law, have forced the state to use resources and its employees to enforce federal gun laws. That could include materially supporting the compilation of gun owner records for the ATF’s gun registry, the enforcement of President Joe Biden’s “zero tolerance” policy against Missouri gun dealers, or helping a hypothetical Kamala Harris administration in confiscating AR-15s under a future “assault weapons” ban.

The precedent is clear, the federal government has no authority whatsoever to compel a state to enforce a federal law. So, what’s the difference here? Sadly, all too many federal judges stubbornly believe the Second Amendment is a second-class right. In the case of the recent ruling against SAPA, the Eighth Circuit simply invoked the Constitution’s supremacy clause, and gave the back of its judicial hand to Missouri and every other state that might question the constitutionality of a federal law — at least a federal gun law.