The eight former Drug Enforcement Administration heads -- along with four former drug czars and assorted anti-drug groups, all under the banner of the Save Our Society From Drugs political action committee -- urged the Senate Judiciary Committee in a letter made public Tuesday to press Holder on why he had taken so long to decide on taking action against the two states, whose voters decided in November to legalize recreational marijuana use.
The letter, which can be found at tinyurl.com/SOSletter, came the same day the U.N. International Narcotics Control Board urged Washington to challenge those states' laws, saying they violated "international drug-control treaties to which the United States is a party."
Holder told a meeting of state attorneys general Feb. 26 he was close to announcing his department's response but was still reviewing the laws.
"I would say -- and I mean this -- that you'll hear soon," Holder said in answer to a question from Colorado Attorney General John Suthers at the National Association of Attorneys General meeting in Washington.
Some observers said they thought Holder might announce his department's response when he testifies before the Senate pane at 9:30 a.m. Wednesday, British newspaper The Guardian reported.
The Justice Department has been studying the two states' laws -- the first in the nation to legalize marijuana's recreational use -- since shortly after the Nov. 6 elections.
By contrast, federal law treats marijuana as a controlled substance like heroin and LSD.
President Barack Obama said in December fighting recreational marijuana use in states that legalized it would not be a high priority of his administration.
"We've got bigger fish to fry," Obama told ABC News in an interview broadcast Dec. 14. "It would not make sense for us to see a top priority as going after recreational users in states that have determined that it's legal."
A poll released last week said 54 percent of registered California voters supported legalizing marijuana for recreational use and subjecting it to similar restrictions to those in place for alcohol.
The Field Poll of 834 registered voters had an error margin of 3.5 percentage points.