Associated Press

PHOENIX — An Arizona lawmaker plans to introduce a proposal next year to legalize recreational marijuana before a similar proposal could get decided by voters in 2016.

Republican Rep. Ethan Orr of Tucson aims to convince fellow conservatives that a voter-approved measure is nearly impossible to change once it is approved and not the way to set up a complex system of rules and taxes for the drug, The Arizona Capitol Times reported Monday (http://bit.ly/ZWCLLV ).

The only way to change voter-approved measures in Arizona is through a two-thirds vote of each the state House and Senate, and the revisions must align with the intent of the measure.

"I would rather us as elected leaders be the ones directing the conversation and the debate, and ultimately controlling the policy, as opposed to letting it go to a citizens' initiative where you can't change the law once it's in place," he said.

Advocates for legal recreational marijuana are aiming to put their proposal on Arizona's ballot in 2016.

Voters have already approved the use of marijuana to treat certain medical conditions such as chronic pain, cancer and muscle spasms.

Republican Rep. Bob Thorpe of Flagstaff said he has concerns about Colorado's legal industry, especially in when it comes to health, use by children and the effect on nearby states. And he said passing a measure in Arizona likely would be impossible politically.

"I think being a Republican and sponsoring a bill that legalizes marijuana might be a third rail," Thorpe said. Something that you really don't want to touch as a Republican because you'll get cooked, especially by the base."

Mason Tvert, a spokesman for the Marijuana Policy Project, which is organizing the 2016 ballot measure, said more libertarian-leaning Republicans favor legalization and opinions in the party are changing along with those of the public.

Tvert said his group is moving forward with the 2016 measure because it's unclear if lawmakers will approve a measure.

There have been other efforts to legalize pot in the state. Former Rep. John Fillmore, a Republican, introduced a bill in 2011, and former Rep. Ruben Gallego, a Democrat, proposed a measure this year — but neither made progress.