Colorado’s neighbors are not happy about marijuana legalization.

The attorneys general of Oklahoma and Nebraska filed a lawsuit on Thursday with the U.S. Supreme Court arguing that Colorado’s commercialized marijuana system violates the constitution.

U.S. Supreme Court building.

“Oklahoma and states surrounding Colorado are being impacted by Colorado’s decision to legalize and promote the commercialization of marijuana which has injured Oklahoma’s ability to enforce our state’s policies against marijuana,” Oklahoma Attorney General Scott Pruitt said in a statement on Thursday, referring to Colorado’s Amendment 64, which legalized marijuana in that state.

In the lawsuit, the states argue that Colorado’s law violates the supremacy clause of the Constitution, which states that federal laws takes precedence over state law.

“In passing and enforcing Amendment 64, the State of Colorado has created a dangerous gap in the federal drug control system enacted by the United States Congress,” they write in the suit. “Marijuana flows from this gap into neighboring states, undermining Plaintiff States’ own marijuana bans, draining their treasuries, and placing stress on their criminal justice systems.”

Read more via Oklahoma and Nebraska are suing Colorado over legalizing marijuana – The Washington Post.