The U.S. Supreme Court on Monday rejected a conservative challenge to the marijuana legalization laws adopted in Colorado and elsewhere that permit adults to buy, sell or use one ounce of the drug.

By a 6-2 vote, the justices turned away a lawsuit brought by Nebraska and Oklahoma, whose state attorneys complained that illegal marijuana was pouring into their states as a result of Colorado’s liberalized laws.

“The state of Colorado authorizes, oversees, protects and profits from a sprawling $100-million-per-month marijuana growing, processing and retailing organization that exported thousands of pounds of marijuana to some 36 states in 2014,” they said. “If this entity were based south of our border, the federal government would prosecute it as a drug cartel.”

They argued that Colorado’s law violates the federal Controlled Substances Act, which treats marijuana as a dangerous drug and forbids its sale or use. They urged the Supreme Court to take up the issue as an “original” matter and declare that Colorado’s law was preempted by the federal drug laws. [Read more at the Los Angeles Times]