Oh, the states.

Those of us educated in one of them have learned since childhood that Federal law is "the law of the land."  When federal law contradicts state law, federal law wins.  State law is rock.  Federal law is paper.  The practical challenges of living together, though, are scissors.

In the last election two states decriminalized marijuana use.  Prior to that, numerous states made it legal for doctors to prescribe marijuana, on a pretty wide variety of pretexts.  Almost everyone I know in California, for example, has prescribed access to marijuana.  My friends and associates are not all sickly people.

Federal law says that all of this is illegal.  The prescribing, the buying, the selling, the dispensing, the possession, the smoking or ingesting... it's all a crime.  That's the law of the land.  What we're hearing from the residents of many states is that they do not like the law of the land.  As a practical matter, the federal government doesn't have the resources to do much about this.  Rooting out local marijuana users is largely a job for local law enforcement, local prosecutors, local courts and local prisons.  If those state resources are directed to leave well enough alone, then we'll get a kind of bottom-up experiment in marijuana legalization.  I hope that the results are good enough to quickly change federal law.  We shall see.  Absent drastic and expensive action that would probably have a lot of unintended bad consequences, the federal government can really do little except to remind people of its supremacy in the abstract and then sit back and watch.

Even the U.S. government has to choose its fights carefully.  Stopping people from using marijuana does not have anything like the moral weight of using federal powers to end segregation.

President Obama was clever when crafting his Affordable Care Act. He gave Republican governors the opportunity to bluster and "opt out" of his health are exchanges, while also empowering the federal government to set up the exchanges for them, if they refused.  This creates an interesting conundrum for the state's rights crowd -- by opting out of a federal program they actually cede power to the federal government.  If they set up their own exchanges, they can make the rules.  If they refuse, Obama will make the rules for them.

Now we hear grumblings about gun regulations.  Mississippi's governor has announced the serious intention to exempt people residing in his state, or manufacturing guns in his state, from any new federal regulations.

This presents a conundrum.  As a matter of law, it's wrong.   Federal laws are supreme.  As a matter of law, it's no different than Colorado legalizing recreational marijuana use and possession.  As a practical matter, if local authorities take the governor's side, the federal government will have limited options.  Using a federal hammer to punish marijuana users in states where it's been legalized, will probably result in bad publicity and much ill will.  Gun standoffs, though, can turn very ugly very fast.

On the other hand, marijuana can't be used to slaughter movie theaters, classrooms or shopping malls full of people.  The government has to set its priorities.  Politely excusing marijuana use in Colorado and Washington, while studying the issue to see if the issue should be turned over to the states entirely, is something that the federal government can do with little consequence and with quiet public support.  Allowing the continued manufacture and sale of high capacity assault weapons isn't quite so easy, particularly is a Mississippi-linked weapon is implicated in another crime after new laws take effect.

As with the rest of life, context is everything.  The rules say that states must follow federal edicts.  The federal government has to be choosy about what it enforces when local authorities refuse to cooperate.  It cannot and should not fight every battle.  States are playing a dangerous game, though.  These disagreements don't always end well.