most laws are based on what the middle class thinks, so if the middle class doesn't think weed is that big of a problem then the punishments will be less severe vice versa
Sorry man, but that's bullshit. It's the people who support the congressmen, and the ones with big pockets who make the decisions, not the middle class.
While for many things this can be true, generally with drugs how the general middle class public percieves them is how the laws are made.