(MCT) — SACRAMENTO, Calif. — In October 2010, with a quixotic marijuana initiative leading in California polls, U.S. Attorney General Eric Holder answered an urgent letter from retired heads of the federal Drug Enforcement Administration.

“Let me state clearly that the Department of Justice strongly opposes Proposition 19,” Holder wrote, declaring he would “vigorously enforce” federal law if California voters passed the measure, which would have legalized recreational marijuana use for adults over 21 and allowed retail sales of pot.