Former Rep. Ron Paul (R-Texas) said on Saturday that Attorney General Jeff Sessions should resign from his post after reversing an Obama-era policy that paved the way for states to legalize recreational marijuana.

"He represents something that is so un-American as far as I'm concerned," Paul, a one-time GOP presidential candidate, said on CNN's "Smerconish." "The war on drugs is a war on liberty."

He said that the federal government does not have the right to "regulate the sale of drugs," and that doing so is "constitutionally questionable."

Paul, who describes himself as a libertarian, has long called for an end to the federal prohibition of marijuana.

His comments on Saturday came days after Sessions rescinded the so-called Cole memo, which discouraged federal prosecutors from bringing marijuana-related charges in states where it had been legalized.

Paul said that the Obama administration made the right move in allowing states to pursue legalization of recreational pot without federal interference. On the other hand, Sessions's decision, he said, violated civil liberties "wholesale."

"Usually I don't ever get involved in these personality squabbles, but this is one major setback," he said. "Obama did something decent there. He backed off and I thought that was a good move. And Sessions wants to reverse that."

Eight states and the District of Columbia have legalized recreational marijuana, and dozens have approved the use of medical marijuana. The substance remains federally prohibited and is considered a Schedule 1 controlled substance, in the same category as heroin and LSD.