Ever since California Gov. Arnold Schwarzenegger signed a bill decriminalizing possession of up to one ounce of marijuana in the Golden State, opponents of Prop 19 have latched onto this development as their latest (bogus) talking point for why voters should reject the ballot measure on Nov. 2. Their argument goes something like this: By making possession a civil infraction rather than a misdemeanor, people will no longer be arrested for marijuana possession in California; therefore, one of the main…