ELECTION 2014: This article is part of our coverage of ballot measures to watch.

If Florida voters authorize medical marijuana in November, they’ll not only make the state the first in the South to legalize the drug for therapeutic reasons. They’ll also make Florida, potentially the third largest market outside of California and New York, one of the only states in the country to enshrine medical marijuana in the state constitution. It would also become one of the only states giving doctors considerable discretion to recommend the drug outside of a specific set of diseases.

It’s on that last point that opponents of Florida’s Amendment 2 have focused the most attention, arguing the measure grants doctors too much leeway. And they’ve raised $3.2 million, mostly with cash from casino magnate Sheldon Adelson, to put the measure down.

But supporters, who have raised even more money in large part with the resources of one sympathetic trial lawyer, appear to have public opinion on their side. Polls have fluctuated wildly, though. The most recent one, released Thursday, pegged support at 57 percent -- tied for the lowest yet -- but backers need to hit 60 percent to pass a constitutional amendment. A Quinnipiac University poll in July put support at 88 percent, six percent higher than another Quinnipiac poll from November 2013.

The lawyer, John Morgan, may have helped get the measure out of the gate with more than $3.5 million in financial support, but he's not doing the campaign many favors lately. A video surfaced last week showing an apparently drunk Morgan at a rally around the time of a medical marijuana debate with the sheriff of Florida's Polk County. Morgan tells an exuberant audience that he "might smoke a lot of grass" once he's out of the sheriff's domain.

Morgan never says he supports full legalization of marijuana, but opponents have pounced over the general tone, Morgan's explitive-laced plea for supporters to vote and the crowd's chants of "smoke weed!" as evidence that Amendment 2 has less to do with getting sick people medicine than expanding marijuana use overall. Amendment 2's proponents say Morgan then went on to talk about a family member who manages chronic pain with the help of marijuana instead of prescription painkillers, which isn't included in the segment of video opponents are promoting online, shown here.

That video could very well weigh on the Amendment 2 campaign, but on the strength of polling so far, proponents argue the public is on their side. They also make another argument that’s likely to resonate in a state considered the center of a nationwide prescription painkiller epidemic in recent years: medical marijuana use reduces addiction to far more harmful drugs. Between 1999 and 2010, states that legalized medical marijuana had 25 percent fewer deaths from painkiller overdoses, according to a study released in August in the Journal of the American Medical Association, which stressed the study proves correlation, not causation.

“I’ve been saying that for the last year and a half,” said Ben Pollara, a Democratic fundraiser managing a campaign for medical marijuana called United for Care. “It’s a nice kind of affirmation that the study has come out, and to a certain extent confirms what I already believe.”

Pollara, like other advocates for medical marijuana, said he’s seen the damage of prescription opiates first hand, and marijuana is a much better alternative for chronic pain.

Marijuana’s potential for relieving chronic pain is one of many therapeutic benefits cited by proponents, but there’s disagreement over the benefits and influential quarters of the medical establishment remain skeptical. The American Medical Association, for instance, doesn’t endorse recreational use or state-based medical programs, but the group -- like others -- supports changing the drug’s status as a highly controlled substance and expediting research. Critics of U.S. drug policy have long wanted the Food and Drug Administration to relax its position on marijuana, saying it discourages research and the kind of formal clinical trials needed to better establish legitimacy.

The University of California at San Diego’s Center for Medicinal Cannabis Research, however, has performed clinical trials since California became the first state to legalize medical marijuana in 1996 and has found the drug provides relief from muscle stiffness and spasms among patients suffering from multiple sclerosis and from pain in patients suffering from serious disorders such as AIDS.

But while the U.S. has been more reluctant to formally study the medicinal benefits of marijuana, Israel has become a research powerhouse and established the drug as a treatment for conditions as varied as post-traumatic stress and Parkinson’s disease. Pollara argues the FDA’s reluctance shouldn’t hold back people who find relief in marijuana.

Florida was already caught up in a wave of recent state laws (many of them in the South) legalizing cannabis oil made from a part of the plant that doesn’t get users high but has gained a foothold in treating epilepsy. Advocates say other southern states will surely follow Florida's lead, because there's already visible support. "The Southern states have been slow to come around in terms of changing policy, despite majority support for medical marijuana, so passing an effective medical marijuana law in Florida would be a big step and hopefully help nearby states realize that it is time to enact compassionate legislation and that these programs can be regulated successfully," said Morgan Fox, the spokesman for the Marijuana Policy Project.

By legalizing medical marijuana that contains THC, the psychoactive ingredient, Florida would join 23 other states and the District of Columbia. Eleven of those states legalized medical marijuana in just the past four years, signaling growing acceptance among the American public, which now narrowly supports full recreational use as well.

All but a few, including California and Massachusetts, however, limit the number of diseases for which a doctor can recommend medicinal marijuana, such as cancer, AIDS, ALS and multiple sclerosis. The language Florida voters will see uses the words “debilitating diseases as determined by a licensed Florida physician,” but in the full text of the amendment, which isn’t visible on the ballot, a debilitating condition is also defined as one “for which a physician believes that the medical use of marijuana would likely outweigh the potential health risks.”

Opponents argued the ballot language is deceptive and will lead to de facto recreational legalization, but the state Supreme Court narrowly upheld the measure with the votes of three Democratic-appointed justices and one appointed by Republican-turned-Democrat Charlie Crist, who’s running against the current Republican officeholder, Rick Scott, for another chance at the governor’s mansion this year.

Calvina Fay, executive director of the Florida-based Drug Free America Foundation, worries about trends such as increased marijuana-related hospitalization in the past decade and increased usage among teenagers, which is linked to lower IQ in adulthood (though two prominent, peer-reviewed journals have released studies undercutting the assertion that legalizing medical marijuana leads to increased use among teenagers).

Fay also worries that medical marijuana is a back door to legalized recreational use or at least makes it far more likely in the future. She is concerned about the permanence of a constitutional amendment and thinks the polling on the issue overstates public support because it doesn’t get into the actual details of the ballot measure, which she thinks will turn off voters as they learn more. She takes the most recent poll as a sign of trouble, because anything less than support well over the 60 percent threshold is a bad sign.

“If it’s polling at 60 percent, I think the other side is in trouble,” she said.