Nebraska and Oklahoma's attorneys general are suing Colorado in the US Supreme Court for legalizing recreational marijuana. The two states, which neighbor Colorado, cited increased law enforcement costs at the border due to stoned drivers and marijuana trafficking. Attorneys general from both states say Colorado is violating federal law and the US Constitution by allowing legalization. Colorado legalized marijuana by ballot referendum in 2012. It allowed businesses to begin selling recreational marijuana in 2014.

Nebraska and Oklahoma say federal law requires a ban

At the heart of Nebraska and Oklahoma's complaint is the claim that Colorado's marijuana legalization law violates federal law and the US Constitution.

The attorneys general of Nebraska and Oklahoma say state-level marijuana legalization violates the US Constitution's Supremacy Clause, which establishes that federal law generally takes precedence over state law. The Controlled Substances Act classifies marijuana as an illegal schedule 1 substance, meaning it's deemed to have no medical value and high potential for abuse. Nebraska and Oklahoma argue that the Controlled Substances Act should overrule Colorado's marijuana legalization law and force the state to keep marijuana illegal.

Neb. Attny Gen: This comes down to a supremacy clause issue. This is whether Colorado law conflicts with the Controlled Substances Act. — Luke Runyon (@LukeRunyon) December 18, 2014

Nebraska not seeking damages for increased law enforcement costs, Neb. AG says this is purely a constitutional question. — Luke Runyon (@LukeRunyon) December 18, 2014



The US Department of Justice has allowed Colorado — and Washington, which also legalized marijuana in 2012 — to allow possession and sales as long as the states meet certain guidelines. But one of the requirements is that Colorado can't allow marijuana to make its way to states where the drug remains illegal — a condition that Oklahoma and Nebraska argue Colorado is violating.

Read the full lawsuit, via the Denver Post: