Colorado Marijuana - A group of ten county sheriffs and two prosecutors from Colorado, Nebraska and Kansas have filed a lawsuit against the state of Colorado for legalizing marijuana.

In lawsuit filed Thursday in a U.S. District Court in Denver, the plaintiffs want Colorado's 2012 Amendment 64 declared "invalid, null and void" because it forces law enforcement officials to choose between fulfilling their oaths to the state or the federal constitution.

" I, my deputies and all law enforcement in Colorado that are subject to the oath both to the United States and to the state of Colorado are in an untenable position," said Chad Day, sheriff of Colorado's Yima County.

"In Colorado every elected official, sheriffs included, are required under the state constitution to take an oath of office," said Sheriff Justin Smith of Larimer County Colorado. "And that oath of office requires that they swear to defend the Constitution of the United State and that state of Colorado. Amendment 64 puts a conflict in those parts of the oath of office."

The plaintiffs also argue that Colorado's legalization of marijuana is causing an undue burden on neighboring states as more people are being arrested for possession. As a result, these surrounding states are forced to spend more money to cover the medial and legal costs of the record number of people arrested for marijuana.

"Colorado's legalization of marijuana has completely changed the landscape involving the marijuana that we encounter," Sheriff Mark Overman of Scott's Bluff County, Nebraska said Thursday during the National Press Club in Washington D.C.

Reports indicate that Colorado Governor John Hickenlooper is named as the defendant in the lawsuit. But several members of the plaintiffs have expressed regret in suing Hickenlooper who said although he was against weed legalization he would work in fulfilling the wishes of voters.

According to his spokeswoman Kathy Green, Hickenlooper has not yet been formally served with the lawsuit.

This is not the first time Colorado has been sued for legalizing marijuana. In late December, Oklahoma and Nebraska sued Colorado over weed.

The lawsuit claims that Amendment 64 violates the U.S. Constitution's Supremacy Clause which states that the federal constitution and federal law "take precedence over state laws, and even state constitutions."

"The lawyers I've talked to don't think that...there's a high likelihood that those suits will prevail," Gov. Hickenlooper said after the Oklahoma and Nebraska lawsuits.

"We're going to do everything we can to make sure there's no black market," he said during an interview early this year. "We clearly haven't gotten there yet, but we are going to redouble our efforts for our own purposes and also for the purpose of the neighboring states."