Talk about your law of unintended consequences. Or in this case, it might be more appropriate to talk about the unintended consequences of a law. Four states have legalized the recreational use of marijuana and nearly two dozen more have medical marijuana provisions. That means that there are businesses selling the wacky weed to consumers, and businesses need to advertise to be competitive. But if they take out an ad in the local paper and expect the post office to deliver it, they’ve got a surprise coming. (WaPo)

In November, Portland’s postal district issued a memo to newspaper publishers, telling them they are breaking the law by running ads for pot and using the U.S. mail to deliver their papers.

The reason? The U.S. Postal Service is a federal entity. Even though Oregon, Washington, Colorado and Alaska have legalized recreational marijuana and 23 other states have legalized medical pot, any newspaper running ads in those states violates a federal law preventing advertising for illicit goods.

The advertising ban, first reported by the Bulletin of Bend, Oregon, prompted an angry letter to postal officials from most Democrats in the state’s congressional delegation to figure out what was going on. Reps. Earl Blumenauer and Suzanne Bonamici and Sens. Ron Wyden and Jeff Merkley accused the Postal Service in a joint statement of being rigid and said the agency should respect the voters’ decision to legalized pot.

This is one of those (hopefully) rare cases where federal and state law come directly into conflict and there was bound to be fallout on a number of levels. Federal agents in the states where pot is legal can choose to turn a blind eye or they can prosecute violators. But when something like this comes out in the open there are going to be other complicating factors, least of which is the taxation question. Still, I’ll confess that I didn’t see this newspaper wrinkle coming.

First of all, somebody at the Post Office surely must have consulted someone in the Justice Department before issuing their warning. If that assumption is correct, then there are still officials in D.C. who are interested in prosecuting pot related cases in states where it’s been legalized. The newspapers can’t publish advertisements for illegal products but it’s pretty hard to demand they serve as their own constitutional scholars and determine whether state or federal law prevails. But the Post Office is a different beast. If Justice told them that it was no big deal they would have no reason to threaten the newspapers.

But even if they stick with this situation as is, who will bring the charges against the newspaper? It won’t happen at the state level so the feds would have to go around and begin busting the owners of newspapers in Oregon. Does that sound likely? It’s still possible that the Post Office is just covering their butts here and nobody will wind up in court, but it would be a fascinating case to watch if they do.