It has been more than seven months since voters in Colorado and Washington State chose to legalize marijuana for recreational use, in contravention of federal drug laws. It has been more than three months since Attorney General Eric Holder Jr. told the Senate Judiciary Committee that he would announce his department’s response to the new statutes “relatively soon.”

So far: nothing. Mr. Holder has yet to indicate whether he will side with all nine former heads of the Drug Enforcement Administration, who published an open letter urging federal pre-emption.

On Monday, the United States Conference of Mayors passed a resolution suggesting the opposite: that the Obama administration should let the states decide this issue for themselves. “Despite the prohibition of marijuana,” the resolution reads, “and the 22 million marijuana arrests that have occurred in the United States since 1965,” some “42 percent of Americans” have used the drug.

Organized crime, the mayors continue, dominates the illegal marketplace; enforcement is not only costly, but also racially biased, with African-Americans far more likely than Caucasians to be arrested for possession despite similar rates of use across ethnic groups. In light of these facts, they say, states should be able to “set whatever marijuana policies work best to improve the public safety and health of their communities.”