On the other side are the usual suspects: The California Narcotics Officers' Association, the California Association of Highway Patrolmen, the California Police Chiefs Association, the California Correctional Supervisors Organization, the California Peace Officers Association, the California District Attorney Association, and local police associations. They are joined by all federal drug czars past and present, past and present DEA administrators, both California US senators and most of the congressional delegation, most newspaper editorial boards, the California Chamber of Commerce, Mothers Against Drunk Driving, the California Beer and Beverage Distributors (who chipped in $10,000 to Public Safety First, a political action committee created to oppose Prop 19), Californians for a Drug-Free Youth, DARE America, and other anti-drug organizations.
PS (14 Oct 2010) The Wall Street Journal chimes in on this point. A piece about 'The economics of drug violence' sums up the opposition to Proposition 19:
Some progress may be in the making on marijuana, and Mexicans will be watching the California ballot initiative that asks the electorate to approve the legalization of the ubiquitous weed. It is far from clear that Proposition 19, as it is known, will pass. The combination of conservatives who fear that legalization would transform us into a hash-happy heap of hippies, drug warriors who make a living off of the criminalization of pot smoking, and gangsters whose profits are tied up in prohibition could be enough to defeat it by a narrow margin.Apart from painting this picture of prohibitionists as self-interested uglies with irrational fears, the article suggests that the War on Drugs 'creates' large, monopolistic and violent drug cartels because that's what it takes to get around military barriers to drug distribution.