On December 18, 2014, Nebraska and Oklahoma asked the U.S. Supreme Court to strike down Colorado‘s legal recreational marijuana system, arguing it violated federal law and pushed marijuana across their borders. On March 21, 2016, the Court refused to hear the case, with Justices Clarence Thomas and Samuel Alito dissenting. It was the most direct legal attack any state ever made on another state’s legalization, and its failure left state marijuana markets standing.
The Weed Street Journal reported on the lawsuit in February 2015, while it was pending. This rewrite covers the full case and how it ended.
What Happened
Colorado voters approved Amendment 64 in November 2012, and licensed recreational stores opened on January 1, 2014. Eleven months later, Nebraska Attorney General Jon Bruning and Oklahoma Attorney General Scott Pruitt filed a motion for leave to file a bill of complaint directly with the Supreme Court, under the Court’s original jurisdiction over disputes between states. The Supreme Court docket, No. 22O144, shows the filing on December 18, 2014.
The two states asked the Court to declare that Colorado’s commercial marijuana system was preempted by the federal Controlled Substances Act and to block it. They did not challenge Colorado’s decision to stop punishing personal use. Their target was the state-licensed growing and selling. They argued that marijuana from Colorado was flowing into their states and straining their police, courts and jails, NPR reported.
Background
Original jurisdiction cases are rare. When one state sues another, it can go straight to the Supreme Court, but the Court has long treated hearing such cases as discretionary and takes few of them. That made the first question not whether Colorado’s law was valid, but whether the justices would hear the case at all.
The suit also exposed an awkward position for the federal government. In August 2013 the Justice Department had issued the Cole memo, which said federal prosecutors would generally not target state-legal marijuana businesses that followed strict rules. Nebraska and Oklahoma were, in effect, asking the Court to enforce a federal law that the federal government itself had chosen not to enforce against Colorado’s market.
What Happened Next
On May 4, 2015, the Court invited the Solicitor General to file a brief giving the views of the United States. Solicitor General Donald Verrilli filed it on December 16, 2015, urging the Court to turn the case away. He argued that Colorado had not authorized anyone to move marijuana across state lines, so the harms the states described were caused by third parties breaking the law, not by Colorado itself. He also warned that the Court’s original jurisdiction should be used “sparingly,” as the National Constitution Center summarized.
On March 21, 2016, the Court issued a one-line order: “Motion for leave to file a bill of complaint DENIED.” The majority gave no explanation. Justice Thomas, joined by Justice Alito, wrote a dissent of about five pages. He did not argue that Colorado’s law was invalid. He argued that the Court should not have disposed of a state-versus-state complaint “so hastily,” and that the states had alleged significant harms to their sovereign interests that deserved a hearing.
By then Bruning had left office. His successor, Nebraska Attorney General Doug Peterson, said he was disappointed and would look at other possible steps. Mason Tvert of the Marijuana Policy Project called the case meritless. Pruitt went on to become administrator of the Environmental Protection Agency in 2017.
The ruling did not decide whether state legalization is preempted by federal law. It only closed the door to this route. We found no similar Supreme Court action by one state against a legalizing neighbor since.
Where It Stands in 2026
All three states have moved since 2014. Colorado’s adult-use market is well established; adults 21 and older can possess up to 2 ounces and grow up to six plants. Oklahoma legalized medical marijuana in 2018 with State Question 788 and built one of the most open medical programs in the country, though voters rejected adult use in 2023. Nebraska voters approved medical cannabis in November 2024, but as of October 2026 no licensed dispensary is open there. Our guides cover each state: Colorado, Oklahoma and Nebraska.
The federal conflict the suit raised has narrowed but not ended. An April 2026 DOJ/DEA order moved state-licensed medical marijuana and FDA-approved products to Schedule III, while adult-use marijuana, including Colorado’s recreational market, remains in Schedule I. Carrying marijuana across state lines is still illegal under federal law. See our federal marijuana laws guide and our state-by-state cannabis laws page.
Nebraska and Oklahoma v. Colorado FAQ
What was Nebraska and Oklahoma v. Colorado?
An original-jurisdiction lawsuit filed in the U.S. Supreme Court on December 18, 2014, asking the Court to declare Colorado’s licensed recreational marijuana system preempted by federal law.
How did the Supreme Court rule?
On March 21, 2016, it denied the states permission to file the complaint, without explanation. Justices Thomas and Alito dissented.
Did the federal government support the lawsuit?
No. Solicitor General Donald Verrilli urged the Court to reject it, arguing that the harms came from people illegally moving marijuana across state lines, not from Colorado’s law.
Did the ruling make state legalization legal under federal law?
No. The Court only declined to hear the case. Adult-use marijuana remains illegal under federal law, and states continue to set their own rules.
Originally reported by The Weed Street Journal; rewritten and updated in October 2026 with what happened next.