No society worth having can function without some malum prohibitum rules.
Now, most of those I've been arguing with should agree with that. In fact, one of the objections I get over and over again stems from equating anarchy with the a-priori absence of all such rules. I'd like to see them try to reconcile what they're arguing against, what they think I am arguing for, with that statement. It can't be done.
For those of you willing to proceed with the understanding that I believe that to be true, I offer the following hypothesis: Government is incapable of generating rational mala prohibitum laws. Not pathologically incapable, but that its very nature contradicts the possibility of doing so. Federalism was, in fact, an attempt (unknowingly) to get around that fundamental flaw in the nature of government, but it merely reduced and masked the effects, it did not address the flaw itself. It was a band-aid over the sores produced by a genetic defect.
Proving it requires a bit more groundwork, and so I'll leave it at that for the moment, as an assertion to be backed up later.