While I support legalization, I'm not sure decriminalization is a very good idea.

The main problem I have with decriminalization is that it continues to leave production and distribution of drugs in the hands of criminal syndicates. That's bad, because it won't actually reduce drug prices (and hence crime levels) very much, and will strengthen the syndicates and weaken support for the real legalization that will take drug dealing out of the hands of the Mafia and Taliban and into the hands of RJR-Nabisco.