By Evan Halper, Tribune Washington Bureau (TNS)

WASHINGTON — When Congress in effect lifted the federal ban on medical marijuana just over a year ago, Californians drove the change, which was tucked into a spending package by a liberal congressman and a conservative colleague.

A year later, marijuana legalization advocates are conflicted over how big a victory the congressional vote, which was repeated last month, has turned out to be.

“The number of raids has dropped substantially, though not completely,” across the country, said Mike Liszewski, government affairs director for Americans for Safe Access, a medical-marijuana advocacy group. A federal court ruling this past fall, if it is upheld, would limit federal agents from targeting all but operations that are clearly flouting state law, he said.

But in California, in particular, federal prosecutors continue to pursue cases, in large part because of flaws in the existing state medical marijuana law, which all sides agree is long overdue for changes. Gov. Jerry Brown has signed three measures to clarify the state law, but they won’t take effect until 2018.

So for now, the state that was the birthplace for legal medical marijuana in the U.S. remains at the center of legal disputes as federal prosecutors navigate a murky landscape in which the line between healers and drug dealers is not always clear.

The two House members who championed the new approach say prosecutors are not following the intent of Congress.

“The will of the people is clear: The majority of the states have enacted medical marijuana laws, Congress has voted twice now to protect those patients, and a federal judge has upheld” the measure, Rep. Sam Farr (D-Calif.) wrote in an email. “How many times does the Justice Department need to be told to back off before it finally sinks in?”

Farr and Rep. Dana Rohrabacher (R-Calif.) teamed up in 2014 to write the measure that said anyone legally selling medical marijuana under a state law cannot be prosecuted.

Officials from the Justice Department declined to comment, citing litigation.

Congress has put the department in a pickle, however. Federal law still classifies marijuana in the most dangerous category of narcotics, alongside heroin and LSD, substances that the law declares lacking any accepted medical use. Congress has declined to change that even as it has approved the Rohrabacher-Farr amendment, as the provision is known.

The city of Oakland is invoking that amendment in demanding federal prosecutors drop their bid to seize marijuana and other assets from Harborside Health Center, the nation’s largest dispensary, which has generated a tax windfall for the cash-strapped city.

Across San Francisco Bay, in Marin County, local officials praised a decision by a a federal judge, who ruled in October that the continued prosecution of a dispensary was an affront to the new law — only to learn last month that prosecutors plan to continue the fight through an appeal.

Complicating matters are the several states that permit the sale of marijuana for recreational use. The Obama administration has chosen to allow that experiment to continue unabated. So operations in California , like Harborside, that target patients seeking the drug to treat illnesses can still be prosecuted while shops in Denver that cater to college students operate freely.

Over the summer, Farr and Rohrabacher accused the Justice Department of illegally misappropriating federal money to continue those prosecutions, calling on for its inspector general to investigate. The department has yet to respond.

Federal officials have argued in court that their prosecutions don’t violate the Rohrabacher-Farr amendment because the occasional bust doesn’t impede the state from allowing the use of medical marijuana. After the judge in the Marin County case rejected that argument as “tortured,” prosecutors are left with the argument that the sales in question are not clearly in compliance with California law, which was written very broadly.

“The early medical marijuana laws were Trojan horses designed to allow effective legalization for anyone who could fake an ache,” said Jonathan Caulkins, a professor of public policy at Carnegie Mellon University in Pittsburgh. “California is in that category.”

Even in the case of Harborside, which state and local officials often hold up as a gold standard for the medical-marijuana business, California’s loose rules about who is permitted to buy medical marijuana have left the operations a natural target for prosecutors, Caulkins said.

“Harborside is gigantic, and the Justice Department thinks it is not providing marijuana just for kids with epilepsy or people with cancer or people with HIV,” Caulkins said.

In states that have more recently adopted medical marijuana provisions, legitimate medical-marijuana businesses are not targeted because they serve a much narrower group of clients, he said.

But the Justice Department’s continued pursuit of Harborside angers officials in Oakland. The business pays the city about $1.4 million annually in taxes.

Advocates hope it is only be a matter of time before the prosecutions subside. California is among several states poised to decide this year whether to legalize marijuana for any adult who chooses to purchase it, whether to treat an illness or to just get high. If the state adopts rules to regulate a legalized market that satisfy the Justice Department — as Colorado and Washington state have done — prosecutors will probably move on to other business.

©2016 Tribune Co. Distributed by Tribune Content Agency, LLC.

Photo: Coaster420 via Wikimedia Commons