You can not be serious. Depending on the source you use, there may be as many as 1 million law enforcement sworn law enforcement officers: "In 2008, state and local law enforcement agencies employed more than 1.1 million persons on a full-time basis, including about 765,000 sworn personnel (defined as those with general arrest powers). Agencies also employed approximately 100,000 part-time employees, including 44,000 sworn officers." This from Wiki so I don't know if the numbers are firm but you get the picture. A large number of these officers are uniformed police that enforce a myriad of laws. If the "drug war" were to end tomorrow, a majority of these officers would still be employed.
Interesting that you state that the majority of police wouldn't have jobs if it wasn't for the drug war when, according to your link, law enforcement made an estimated 13,687,241 arrests (except traffic violations) nationwide in 2009. Of these arrests, 581,765 were for violent crimes and 1,728,285 were for property crimes. In other words, drug arrests accounted for approximately 11% of those arrested. In fact, more people were arrested for property crimes but I don't hear you calling for legalizing them. In addition, "possession" is a vague word in the sense that you don;t know if someone was arrested for 1 gram or 100 kilos of any particular drug so I'm not sure that mere possession implies a less serious offense.
Again, from your own link, a vast majority of arrests are for non-drug related offenses. And what "impact" do properly laws have when they account for more arrests than drugs? Why aren't you making that argument when it comes to other crimes that account for more arrests?