Sen. Tom Coburn predicts the experiment with legalized marijuana will "end up a tragedy." Still, he believes it is a states' rights issue, and each state should make its own decision on legalization.
Washington became the second state Tuesday to legalize recreational pot use, and Coburn, who is a medical doctor, detailed the drug's harms on CNN's "Crossfire."
"There's never been a positive study on recreational marijuana," the Oklahoma Republican said, adding that all the information he has read links pot to further drug use, depression and lack of motivation. The carcinogens in one marijuana joint are equal to those in 18 tobacco cigarettes, he said.
"There's nothing really positive that comes out of it," Coburn said.
Colorado also allows recreational use, and 23 states and the District of Columbia allow marijuana use for medical purposes. Coburn said he favors people using the drug in pill form when taking it medically.
Switching to his legislator role, Coburn said that since the federal government still lists marijuana as a controlled substance, states shouldn't be legalizing it.
The federal government should either remove pot from its controlled substance list or enforce its own laws, Coburn said. But since he is an advocate of states' rights, Coburn said he favors federal decriminalization, which would allow states to do as they please.
"But it's still stupid," he said. "We're free to be stupid in this country. And it's really stupid in Colorado right now."
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