Just weeks before the one-year anniversary of legal marijuana in Colorado, the state's status as breaker of the green ceiling is under assault from an unlikely source: its neighbors. On Thursday, Oklahoma Attorney General Scott Pruitt announced that his state was teaming up with Nebraska to petition the Supreme Court to declare legal marijuana in Colorado "unconstitutional."    

Fundamentally, Oklahoma and states surrounding Colorado are being impacted by Colorado’s decision to legalize and promote the commercialization of marijuana.

Their main gripe is that weed is wending its way into their states from Colorado, which neighbors both Oklahoma and Nebraska. Marijuana is still illegal at the federal level although earlier this week, Congress formally ended the federal ban on medical marijuana.

This lawsuit has set off a regional war between the top lawyers in the states. Colorado Attorney General John Suthers responded by saying the initiative is "without merit" and that Colorado would fight the suit in the Supreme Court.

Morgan Fox, who manages communications for the Marijuana Policy Project, brushed off the lawsuit. He helped to shepherd Colorado's legalization effort in 2012.

"Marijuana was widely available in Nebraska and Oklahoma well before Colorado made it legal," he said, adding that "it would continue to be available even if Colorado were to all of sudden make it illegal again." Fox also noted that if the lawsuit were successful "it would only make regulation [of marijuana] in Colorado illegal. Marijuana possession would still be legal."

Colorado's attorney general said pretty much the same thing, explaining that the lawsuit as it stands challenges the "non-enforcement of federal laws regarding marijuana, as opposed to choices made by the voters of Colorado."

While the success of this legal challenge seems unlikely, it does represent the ongoing nature of the battle over legal marijuana. The emergence of a regional opposition to legalization seems compelling as well; Washington, the second state where marijuana was made legal, was not included in the lawsuit. It's also unclear if the attorneys general of Oklahoma and Nebraska sought out their counterparts in Wyoming, Utah, Kansas, New Mexico, and Arizona, all of which also border Colorado.

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