Once allies in the anti-anti-drug movement, groups supporting full legalization of the drug — medical and recreational — and the medical marijuana industry are beginning to clash, with the medical marijuana lobby actively fighting bills to decriminalize the drug.

Medical use of marijuana has been approved in 19 states and the District of Columbia. This past Tuesday, New Hampshire became the latest state to approve medical use of pot, with some of the strictest regulations in the country.

In neighboring Maine, where medical marijuana was approved by state legislatures in 1999, a bill to legalize the possession of marijuana and tax the drug was struck down last month. The "Big Marijuana" lobby vociferously opposed the law, citing an unfeasible, unfair tax structure and the possibility that criminals would smuggle marijuana across state lines.

"The main objections came from the fact that the bill was not built around Maine's medical marijuana industry," Paul McCarrier, a lobbyist for the Medical Marijuana Caregivers of Maine, told POLITICO. "Philosophically, were not opposed to the decriminalization of marijuana, but the devil is in the details."

But some, particularly those fighting for the full legalization of marijuana, would argue that the medical marijuana industry was motivated by the other kind of green.

Big Pharma, Meet Big Marijuana

The legalization of medical marijuana has given countless many living with chronic illness the chance to control symptoms of nausea, weight loss, and pain. It has also led to the development of a billion dollar industry that enjoys exclusive monopolies on legal (at least, on the state level) marijuana production and sale. While the industry is technically illegal under federal law, the criminalization of marijuana keeps the prices high.

"There are people who are benefiting financially and would prefer to see nothing change that," Erik Altieri, communications director for the National Organization for the Reform of Marijuana Laws, told POLITICO.

Dispensaries operate under the constant threat of Internal Revenue Service audits and high-profile drug raids. Last Wednesday, the Drug Enforcement Agency executed several search warrants at Seattle medical marijuana dispensaries, seizing several thousands of dollars of marijuana. The state of Washington legalized recreational use of marijuana during the 2008 election. That bill, too, was met with opposition from medical marijuana groups, who said the law would put them out of business.

In contrast, Colorado's effort to decriminalize pot possession passed with little vocal opposition from Big Marijuana. Medical marijuana lobbyists did manage to sneak a concession into the bill: Medical marijuana dispensaries have first dibs to convert themselves to recreational dispensaries before anyone else can apply for licenses.

Public Opinion Changes Rapidly, While Federal Policy Does Not

Public opinion on legalizing marijuana hit a milestone this year, when a national Pew Research poll found that for the first time the majority of adults — 52 percent — supported the full legalization of marijuana. The percentage of adults supporting legalization is up 11 percentage points from 2010.

On the medical front, 76 percent of doctors internationally, polled throught the New England Journal of Medicine website agreed that the benefits of medical marijuana outweigh the risks.

But the federal government has taken no part in this liberalization of attitudes. Marijuana is still classified as a Schedule I drug, meaning it's deemed to have a high potential for abuse and no accepted medical benefit. There's little effort in Washington to reclassify the drug, and the Drug Enforcement Agency and Internal Revenue Services are treating dispensaries as criminal.

"Marijuana is illegal 24 hours a day, 7 days a week under federal law," said Douglas Hiatt, criminal defense attorney. "There is no defense, there is no justification."

With half of adults admitting to trying pot and over a third of states legalizing medical marijuana, it might be time for the federal government to reconsider their failing policies.