Agreed, but PART of Penn's argument, if you want the video, is that Obama's beyond hypocritical - and it's a class thing - to be smug and show how cool he is in front of a bunch of college students by saying he smoked 'weed' and 'maybe did a little blow.'
Obama even phrased it as if the act itself made him hip and cool.
After that, Penn pointed out that one in six people in jail are there for a pot-related crime (I can't believe they were all for possession). But I'll take Penn's argument about Obama's smugness and trying to make his own drug use sound cool- while cracking down on others for doing what he's trying to make look hip and cocky and cool.
Hell, Obama even told everyone he was making federal enforcement against medical marijuana users the lowest priority of the DEA, but a couple years later, he started up with the busts again. If I was a liberal pothead, I think I would feel betrayed.