U.S. Capitol (Associated Press)

So the federal government, the Department of Justice announced today, is backing off its previous confrontations with legal (by state law) marijuana.

My first reaction? Hey, all those folks who had been blasting the president for years now because of draconian enforcement of drug laws were once again, as with many other critics of the president, proved wrong; the federal government (as conservatives remind everyone constantly) is large, and that means it sometimes takes time to change policy. Obama’s critics jumped the gun. I suspect it’s going to be easy now to go back and find over-the-top complaints about the president on this issue that are now proved, well, over the top. Just as I think one could find similar statements about “don’t ask, don’t tell,” or marriage equality, or exiting Iraq, or getting bogged down in Libya.

My second reaction, however, is that my first reaction is garbage.

Because of course those over-the-top complaints were part of the political landscape that Democrats in Congress and the White House had to deal with when they made the decisions that eventually satisfied, at least to some extent, the activists who were making the complaints in the first place.

So why am I telling you this? It’s just worth stopping every once in a while and noting something we all tend to undervalue — that different people within the political system have different jobs to do. The job of an activist may involve going over the top at times (although not always; there’s value in being accurate). And the jobs of the others within the system — presidents, political appointees at the top of departments and agencies, bureaucrats below them, members of Congress — are all similarly constrained by various rules, norms, and incentives.

Which isn’t to say that everything works out in the end — sometimes it does, but no question about it, sometimes it doesn’t. At best, it’s just a reminder to keep all of our arrogance a tick lower. Or at least to remind everyone that there are often perfectly good reasons why political actors act as they do, and that anyone seeking to change those actions often has to change the incentives more than anything else.