DENVER — Should marijuana be treated like alcohol? Or should it remain in the same legal category as heroin and the most dangerous drugs? Votes this week by Colorado and Washington to allow adult marijuana possession have prompted what could be a turning point in the nation’s conflicted and confusing war on drugs.

U.S. Attorney General Eric Holder was to talk Friday by phone with Colorado’s governor, who wants to know whether the federal government would sue to block the marijuana measures. Both states are holding off on plans to regulate and tax the drug while waiting to see whether the U.S. Justice Department would assert federal authority over drug law.

The Obama administration has largely turned a blind eye to the 17 states that currently flout federal drug law by allowing people with certain medical conditions to use pot, something banned under federal law.

“In a situation like this, where our law is at loggerheads with federal law, my primary job is to listen first,” Colorado Gov. John Hickenlooper said Wednesday.

Hickenlooper opposed the ballot measure and has downplayed the likelihood of a commercial marijuana market materializing in Colorado.

“Based on federal law, if it’s still illegal under federal law, I can’t imagine that 7-Eleven is ever going to sell it,” he said.

Meanwhile, marijuana activists are waiting for a Washington, D.C., federal appeals court to decide whether marijuana should be reclassified from its status as a dangerous drug with no accepted medical use.

Last year, the Drug Enforcement Administration rejected a petition by medical marijuana advocates to change the classification, which kept marijuana in the same category as drugs such as heroin. Reclassification of marijuana could open the door for more research into its medical use.

Marijuana advocates hope the federal government maintains its current posture of mostly ignoring states that flout federal law by allowing medical use under certain circumstances.

The U.S. has cracked down during the past two years on more than 500 marijuana dispensaries in several states, but no one has faced federal prosecution for personal use.

“It would certainly be a travesty if the Obama administration used its power to impose marijuana prohibition upon a state whose people have declared, through the democratic process, that they want it to end,” said Brian Vicente, co-author of Colorado’s marijuana measure.

Earlier this week, Justice Department spokeswoman Nanda Chitre said enforcement of the federal Controlled Substances Act remained unchanged.

Eric Brown, a spokesman for Hickenlooper, would not say whether the governor planned to disclose the details of his call with Holder.

If Colorado’s marijuana ballot measure is not blocked, it would take effect by Jan. 5, the deadline for the governor to add the amendment to the state constitution. The measure allows adults to possess up to an ounce of marijuana, and six marijuana plants, though public use of the drug and driving while intoxicated are prohibited.

Colorado’s measure also directs lawmakers to write regulations on how pot can be sold, with commercial sales possible by 2014.

In Washington state, marijuana possession of an ounce or less would become legal on Dec. 6 if the measure is not blocked, though setting up a state-run sales operation would take a year.