Anti-weed supporters have contributed almost four times more cash than pro-week supporters.
The effort to legalize recreational marijuana in Arizona might be an uphill climb, at least according to spending on the initiative.
An ABC15 analysis of Proposition 205 spending found that those opposing pot have outspent those who support pot by more than six to one.
Independent experts we spoke with said the legalization of recreational marijuana has become a national issue.
Brad Rowe is president of Los Angeles-based BOTEC Analysis, a research firm that focuses on drug policy. He said it is "now or never" for those both for and against marijuana.
"This is a very critical window," Rowe said.
Besides Arizona, four other states have marijuana on their November ballots -- California, Maine, Massachusetts and Nevada.
Gregory Midgette, a policy researcher at the RAND Corporation, said the successful passage of legalization in Washington and Colorado put weed center stage.
"Those actions have brought the idea of legalization," Midgette said. "There is national interest in state-level politics."
As for Arizona, a large percentage of contributions from those in favor of pot have come from outside the state.
Midgette said there may be financial motivation.
"It's hard to guess why," he said.
Take a look at the full map below to see where -- and how much -- people have donated for and against Prop 205: