While it's true that those groups profit from prohibition, it's not as though the status quo is maintained
in order to help the dealers. And many law enforcement groups are against prohibition, or at least decriminalizing possession in small quantities.
The biggest obstacle to reform by far is the one-two punch of ignorance and cowardice. Most voting publics think that prohibition is a good thing, and most politicians don't want to be hammered by their opponents as soft on crime/pro-drugs, etc.
Governor Schwarzenegger's support for
a debate on the matter, however, might give us cause for hope...
Anyway, I never used the stuff, not sure if I ever will.