That's your opinion, but I don't think that the US Constitution stands on the right to smoke dope anytime, anywhere.
This is a strawman. No one is suggesting that people should be able to smoke marijuana anytime anywhere. People aren't being arrested for smoking and driving or smoking and committing crimes, they're arrested for simple posession of a non-toxic plant. There can be no justification for persecuting marijuana users in a free society, and if we were a socialist society that locks up people for harming only themselves it would be the tobacco and alcohol users who got locked up. Any way you look at it marijuana prohibition makes no sense.