One of the country's leading drug policy reformers visited Oregon Tuesday to make a pitch for legalizing pot, calling the recreational marijuana initiative headed to the November ballot "the new gold standard" of marijuana reform efforts.

Ethan Nadelmann, executive director of the Drug Policy Alliance, called Oregon's effort to legalize marijuana is "the No. 1 priority " for his New York-based organization. The political arm of Nadelmann's group has so far contributed about $650,000 to New Approach Oregon's marijuana legalization campaign.

"Colorado has been up and running for six months and the initial reports clearly indicate the sky is not falling," said Nadelmann. "There is a lot of spin on both sides, but not that much has changed except you have the emergence of a legal industry."

Nadelmann acknowledged some key challenges that come with legalization, including how to deal with impaired driving and standards for marijuana-infused edible products, such as cookies and other treats. Colorado and Washington have grappled with questions of dosing, testing and packaging for marijuana-infused foods, which in Colorado have led to high-profile cases of over-ingestion.

Nadelmann said overeating a brownie baked with marijuana butter isn't fatal, but he said food products "present challenges in terms of standardization."

Kopilak said the initiative reflects the work of not only advocates but also national tax experts, including Pat Oglesby, chief tax counsel on the U.S. Senate Finance Committee from 1988 and 1990.

On Oglesby's advice, New Approach Oregon opted to tax marijuana by weight early in the production process instead of at the retail end. Washington, by comparison, taxes marijuana at three levels, from producer to processor, processor to retailer and retailer to consumer. "It's hard to see how people make money in Washington on this," said Kopilak.

New Approach Oregon also sought the advice of two veteran prosecutors, Norm Frink and Mark McDonnell, both of whom have retired from the Multnomah County District Attorney's Office. Kopilak said it was Frink and McDonnell who strongly encouraged advocates to reduce personal possession limits from the 24 ounces allowed under the state's medical marijuana law to 8 ounces.

He said the former prosecutors also wanted to ensure that penalties remained in place for people not in compliance with the law.

The initiative allows local governments to opt out, but such a move would be decided by a local ballot initiative every two years. Communities that opt out would not get tax revenue generated by marijuana sales.

Under the initiative, revenue would be distributed according this formula: 40 percent to the common school fund; 20 percent to mental health, alcoholism and drug services; 5 percent to the Oregon Health Authority for drug abuse prevention; 15 percent for Oregon State Police; 10 percent to cities for law enforcement and 10 percent to counties for law enforcement.

Opponents of legalization worry about adolescent marijuana use. They argue that increased acceptance and availability will lead to increased marijuana consumption by teens. But Nadelmann said adolescents won't be the prime market for marijuana consumption in a legal market. Instead, he said people 40 and older will turn to the drug for to help them relax, get relief from chronic illness and improve their sex lives.

"People who are finding that taking a little bite off that marijuana pretzel each evening is better than the Ambien or taking a puff off a vaporizer while watching the 'Late Show' is preferable to a drink," he said. Opponents argue that Oregon already decriminalized small amounts of marijuana decades ago.

Possession of less than an ounce of marijuana is considered a violation that doesn't result in arrest or jail.

"We are talking about Oregon, not Texas, not Georgia and not the federal government," said Clatstop County District Attorney Josh Marquis.

Marquis said New Approach Oregon representatives have misstated Oregon's record on marijuana arrests given that most are violations. The group cited a Oregon State Police report that showed 12,808 marijuana-related arrests in 2012; the vast majority were for violation-level offenses.

-- Noelle Crombie