Las Vegas casino magnate Sheldon Adelson is singlehandedly responsible for roughly one-third of all anti-legalization spending this year, a total of $3.5 million in three states so far. Las Vegas Sands Corp. Chairman and CEO Sheldon Adelson testifies in court Monday, May 4, 2015, in Las Vegas. (John Locher, The Associated Press)

A casino magnate’s spending millions against pot. Here’s who’s also donating for (and against) legalization

With five states voting on marijuana legalization next month, this is a pivotal year for marijuana policy no matter which way the contests turn out. The results will determine whether marijuana reform gains momentum heading into the next presidential administration or whether the pace of change will slow.

Businesses, interest groups and individuals have spent roughly $40 million dollars so far this year to support or oppose the measures on the November ballots, according to a Washington Post analysis of campaign finance records from the five states and Ballotpedia. Most of that campaign cash — about $29 million of it — has flowed to the pro-legalization side of the ledger. Legalization supporters have raised close to $20 million in California alone.

But the coalition of groups funding campaigns for or against marijuana vary drastically from state to state. Proponents have accused various industries — like pharma, alcohol or gambling — of playing outsized roles in the opposition to marijuana reform in order to protect their own interests. While these industries have shelled out hundreds of thousands of dollars for campaigns fighting against legalization in several states, campaign finance data suggests that no single interest dominates the marijuana campaign-funding landscape.

In most of the states, wealthy individual donors and small businesses, along with drug policy advocacy groups, have funneled far more dollars to the opposition than casinos, alcohol or the pharmaceutical industry. For example, Las Vegas casino magnate Sheldon Adelson is singlehandedly responsible for roughly one-third of all anti-legalization spending this year, a total of $3.5 million in three states so far.

Here is is an overview of 2016 marijuana donations in each of the five states considering legalization.

California, the nation’s most populous state and the world’s sixth-largest economy, has long been the crown jewel among marijuana advocates’ state-level aspirations. As such, the state represents well over half of total marijuana legalization fundraising in 2016.

California stands out for the outsize role of individual wealthy donors have played in campaign funding. On the pro-legalization side, Napster founder Sean Parker has given millions to the cause, according to California Secretary of State records. The lion’s share of money to the opposition, more than $1 million of it, has come from wealthy East Coast retired art professor Julie Schauer, who has argued that marijuana is linked to violent behavior.

These numbers may understate the role of wealthy individual donors in California. On the pro-legalization side, for instance, the Sacramento Bee reports that at least $4 million in funds donated by Drug Policy Action, the advocacy arm of the Drug Policy Alliance, appears to have come from billionaire philanthropist George Soros.

Such advocacy groups make up the second-biggest category of funders of marijuana-related causes in California, like the Drug Policy Alliance (for legal marijuana) and Smart Approaches to Marijuana (against it).

The opposition in California is also notable for receiving numerous small donations from various law enforcement associations and individual officers, adding up to about 5 percent of their total haul so far. Law enforcement groups have traditionally been among the most outspoken opponents of marijuana legalization, but so far this year they’ve only been making a significant financial push against California’s measure.

While individual donors dominate the California landscape, business entities are the key players in Nevada’s ballot initiative. More than 40 percent of the $2 million given in support of legalization has come from various dispensaries and companies involved with the state’s medical marijuana industry, according to Nevada Secretary of State records.

Businesses unrelated to the marijuana industry are also playing a big role on the pro-legalization side of the ledger in Nevada, though some may have hidden interests in the measures. For instance, the Law Offices of Brian Padgett has donated $150,000 in support of legalization this year; though the law firm focuses on landowner rights, Padget himself is an investor in CW Nevada, a dispensary offering marijuana-based treatments for epilepsy patients.

Opponents of legalization in Nevada are keeping pace with supporters for donations. That opposition money comes almost exclusively from the gambling industry or individuals closely affiliated with it. Casino magnate Sheldon Adelson has given $2 million to the anti-legalization effort in Nevada, according to the Secretary of State.

Mason Tvert, director of communications for the pro-legalization group Marijuana Policy Project, suggested Adelson’s opposition is fueled by his business interests.

“If you like drinking alcohol and playing blackjack at the casino, Mr. Adelson wants you to be his guest,” Tvert said in an email. “If you prefer to consume marijuana while playing video games in the privacy of your home, Mr. Adelson wants you to be in jail.”

Adelson also contributed $1 million this year to fight a medical marijuana measure in Florida, after funneling $5 million into a successful effort to stop a similar ballot initiative in 2014.

Attempts to reach Adelson for comment were unsuccessful. But his supporters say the billionaire’s crusade against marijuana should be seen as an individual decision rather than a business one. Adelson has had two sons who have struggled with drug addiction, one of whom lost his life in 2005. His wife, Miriam Adelson, is a doctor specializing in drug addiction.

“This is a case of someone who’s been touched very deeply by drug abuse,” said Kevin Sabet of Smart Approaches to Marijuana in an email. Sabet points out that legalization supporters have received much of their own financial support from billionaire backers like George Soros and the late Peter B. Lewis of Progressive Insurance.

South Point Hotel & Casino, MGM Resorts International and Boyd Gaming Corp. are also among the top five donors to the anti-legalization cause. The American Gaming Association, a lobbying group for the gambling industry, refused to comment.

Sheldon Adelson is also flexing his muscle in neighboring Arizona, where he recently contributed $500,000 to fight legalization. Pharma is making its presence known in Arizona as well, with a half million dollar contribution from Insys Therapeutics, a painkiller manufacturer that is developing a drug based on a synthetic version of THC, the primary ingredient in marijuana, that’s used to treat nausea and weight loss issues in cancer and AIDS patients.

But the Insys donation stands out for being the only pharma contribution against legalization this election cycle in any state.

Arizona is also interesting for the broad array businesses from multiple industries chipping in to fight legalization. Since Oct. 1, the opposition has received significant infusions of cash from the Arizona Chamber of Commerce & Industry ($498,000), heavy equipment supplier Empire Southwest ($150,000) and Discount Tire ($1,000,000), to name a few.

The founder of Discount Tire, Bruce Halle, is an ally of Arizona governor Doug Ducey, who has been a vocal opponent of the legalization initiative, and who has played a key role in fundraising for the opposition. Ducey’s efforts on behalf of the opposition to legalization may explain why Discount Tire and other Nevada businesses have been quicker to line up against legalization than in other states.

Like Nevada, support for legalization in Arizona comes primarily from various businesses working in the medical marijuana industry, and from reform groups like the Marijuana Policy Project.

Heading over to the East Coast, Adelson is again a key player in Massachusetts. His $1 million donation to the fight against legalization represents close to two-thirds of the opponents’ total haul.

The health-care industry in Massachusetts, including a number of hospitals, has also given big to the fight against marijuana legalization there. The Massachusetts Hospital Association voted to oppose the measure for public health reasons and concerns about the drug becoming accessible to children, though the measure would restrict marijuana use to adults over age 21.

The state’s alcohol industry is another significant contributor, giving a total of $75,000 to the fight against pot.

Similar to the situation in Arizona, Massachusetts’ governor has been outspoken on his opposition to legal weed and has been active in fundraising against the measure.

On the support side, nearly all of the money has come from drug policy advocacy groups. Chief among those has been the New Approach PAC, a D.C. group. Other notable pro-legalization donations include $100,000 from Rick Steves, the host of radio and television travel shows. Steves is a vocal advocate of drug policy reform and sits on the board of NORML, the National Association for the Reform of Marijuana Laws.

Maine’s marijuana contest stands out for the small amounts of money involved — just $1.3 million in support of legalization, and only $79,050 opposed to it. Most of that money comes from drug policy advocacy groups, including the Marijuana Policy Project and the New Approach PAC.

Most of the money opposing legalization in Maine has come from the Alliance for Healthy Marijuana Policy, a group based in Alexandria, Virginia.

Other legalization backers are concerned that the campaign finance numbers suggest that existing medical marijuana businesses aren’t huge backers of legalization in states like Maine and Massachusetts.

“Many marijuana industry companies don’t really seem to be doing their part in helping to build the movement and ensure victories,” said Tom Angell of the pro-legalization group Marijuana Majority in an email. “If we lose most or all of the measures, the industry will surely come to regret assuming that marijuana would legalize itself or that someone else would donate needed funds to help get out the vote.”

Taylor West, deputy director of the National Cannabis Industry Association, said in an interview that “being involved in the political process is an inherent part of being in this industry,” and that “NCIA and other organizations and companies have been preaching that message for the past year.”

But, she added, the industry is still relatively new. Many marijuana businesses are currently operating as start-ups and lack excess capital to support ballot initiatives. Some are also preoccupied with regulatory issues at the state and local level.

“There are a lot of competing pulls on a relatively small pool of funds for these efforts,” West said.

Polls generally show that legalization advocates are enjoying a slight edge in support, but with two weeks until election day the margins are close enough that the measures could easily go either way.