In a phone interview with The Associated Press, Director of National Drug Control Policy Gil Kerlikowske said Justice Department officials are "looking at all their options" for responding to the measure, which would conflict with federal laws classifying marijuana as an illegal drug.
Among them, he said, is following the recommendation nine of the nation's former Drug Enforcement Agency chiefs made last month in a letter to Attorney General Eric Holder: having Obama sue to overturn Proposition 19 as an affront to federal authority.
"The letter from the former DEA administrators, a number of whom are not only practicing attorneys but former state attorney generals, made it very clear that they felt that pre-emption was certainly applicable in this case," said Kerlikowske, the former police chief of Seattle.
Holder told the former DEA heads last week that that the U.S. government plans to "vigorously enforce" federal laws outlawing marijuana possession and distribution even if the activities are allowed under state law. But the attorney general did not respond directly to their suggestion that the administration should go to court if California passes the first-of-its-kind measure aimed at treating marijuana the same as alcohol.
Proposition 19, a state constitutional amendment on the November ballot, would allow adults at least 21 years old to possess up to 1 ounce of marijuana and grow 25-square-foot pot gardens for personal pleasure. It would also authorize county and city governments to regulate and tax commercial cultivation and sales.
Kerlikowske was in Southern California on Wednesday for a visit to a Pasadena drug treatment center where he planned to discuss new government data on marijuana abuse in California.