Source: Flickr user Free Photos.

Whether you realize it or not, the debate over whether or not to legalize marijuana is no longer just an issue for Main Street to deal with. Wall Street has taken notice of the momentum behind the marijuana movement, and some of the world's most influential business leaders and CEOs have begun issuing their opinions on what should happen with marijuana going forward.

These business leaders have thrown their support behind marijuana
As you might imagine, speaking out about marijuana now isn't as taboo as it may have been as recently as a decade ago; three major polling groups -- Gallup, Pew Research, and General Social Survey -- all suggest that a slight majority of Americans now have a favorable view of marijuana. It also doesn't hurt that four states have legalized the drug for recreational purposes (with a fifth, Ohio, potentially on the way this November), and nearly two-dozen states allow for the sale of marijuana for medicinal purposes.

Nonetheless, marijuana remains a federally illegal drug, and discussing marijuana as a high-profile business leader is still somewhat unexpected. However, five business leaders have thrown caution to the wind and been quite forthcoming with their support of the marijuana legalization movement.

In no particular order, here are those five business leaders.

George Soros. Source: Flickr user Norwegian Mission to the UN.

1. George Soros, founder and chairman of Soros Fund Management
One of the oldest supporters of marijuana is also one of the world's wealthiest people, according to Forbes.

In October 2010, Soros published an op-ed in The Wall Street Journal outlining why he is such an ardent supporter of marijuana legalization. Front and center to Soros' argument is that regulating and taxing marijuana would generate billions in tax dollars, while simultaneously saving billions in "enforcement and incarceration costs."

Soros also confronts the concerns parents might have regarding their children's exposure to a tide of marijuana hitting the market. Soros suggests that "honest and effective drug education" is the key to keeping our kids safe and informed.

Source: Richard Branson.

2. Richard Branson, founder of Virgin Group
While not boasting a net worth of $24 billion and change like Soros, Virgin Group founder Richard Branson is far from a pauper, with a net worth of $5 billion according to Forbes

Branson is an admitted user of recreational marijuana, and has been an outspoken advocate of ending the war on drugs. In LinkedIn's Big Ideas 2013 series, Branson had the following to say:

"[T]he trillion dollar war on drugs has persisted for 40 years even though it is the most dismal global policy failure of our time. Millions of otherwise productive lives are wasted in jail for marijuana possession and other nonviolent drug violations. California alone could raise an estimated $1.4 billion in annual revenue if it taxed and regulated the sale of marijuana -- so imagine the revenue that is keeping the underworld in business."

John Mackey. Source: Whole Foods Market.

3. John Mackey, co-CEO and co-founder of Whole Foods Market
John Mackey, one of the co-founders and current co-CEOs of organic and natural grocery chain Whole Foods Market, has long been a proponent of liberal reforms. Aside from wanting to give consumers more healthful food choices, and capping the pay of executives at no more than 19 times the average pay of a Whole Foods employee, in an interview with Mother Jones in 2013 Mackey said the following:

"[I] often self-identify as a 'classic liberal.' I am pro-choice... [and] marijuana legalization." 

Further, Troy Dayton, the CEO of ArcView Group, has suggested that Whole Foods could become a retailer of gourmet cannabis products. Co-CEO Mackey has said that such a strategy would only happen if the plant were legal and its stores had the support of the local community, but he didn't dismiss the idea, either.

4. Peter Thiel, PayPal co-founder and venture capitalist
Peter Thiel, one of the co-founders of PayPal and a well-renowned venture capitalist currently worth $2.8 billion according to Forbes, is another ardent supporter (and investor) in the marijuana movement.

Peter Thiel. Source: Flickr user Heisenberg Media.

When speaking at the Launch Festival in San Francisco this past March, Thiel had this to say:

"[I don't] think there's anything unusual about cannabis... this is a trend that is happening and will continue to happen."

This comment from Thiel follows a move last year by his venture capital firm, Founders Fund, which made a $75 million investment in Privateer, a company looking to access a number of facets of the marijuana supply chain. Privateer is exploring the idea of a testing facility in Washington state, and has already generated revenue by mailing medical marijuana to eligible patients. It also owns Leafly, which is a user review website for marijuana products.

Source: George Zimmer.

5. George Zimmer, founder and former CEO of Men's Wearhouse
Lastly, just last week the founder and former CEO of the Men's Wearhouse (who's once again back in the saddle with his newest competing company, Generation Tux) announced on CNBC that he's been a cannabis user for about 50 years. Not surprisingly, Zimmer noted that he's throwing his full support behind next year's initiative to legalize marijuana in California.

Calling the ban on marijuana the "biggest con ever perpetrated," in his interview on CNBC, Zimmer had this to say at the Cannabis World Congress & Business Expo in Los Angeles:

"Everybody in this country knows what the truth here is, except the 535 people we elect to make these decisions in Washington D.C."

Zimmer also addressed tax concerns that marijuana businesses are currently facing:

"There are still a lot of questions that are raised in terms of dispensaries, and the way the IRS does not allow normal business deductions."

What this means for the marijuana movement
If anything, the support of five very well-known, rich, and influential business leaders demonstrates that the marijuana movement isn't one to be ignored. As long as marijuana has the support of a handful of influential business leaders, the movement will likely have enough advertising power to reach its target audience, the American voter.

Of course, all the money and influence these business leaders possess may not be enough to change the minds of America's lawmakers.

Source: White House on Flickr.

For starters, Congress is still unsure of the long-term safety of marijuana. Even though we've witnessed a handful of clinical studies hitting the newswires that demonstrate the potential medical benefits of marijuana, most research for the past couple of decades has only examined its risks. Until there is sufficient long-term data in the hands of lawmakers that exhibits the safety of marijuana on users' bodies and minds, we likely won't see a change in marijuana's scheduling at the federal level.

As long as there's no change in this aspect, we're also unlikely to see the financial disadvantages the industry faces lighten. U.S. tax code 280E will continue preventing marijuana businesses from taking normal tax deductions, and access to basic banking services will probably remain challenged as financial institutions stick to the sidelines in fear of facing eventual prosecution or loan losses down the road.

I don't doubt that marijuana will remain a hot-button issue for the near future, but I also don't believe that it'll be an investment-worthy product for a long time (if ever). My suggestion now remains the same as it has been: your money would be best served by looking toward other high-growth opportunities.