Colorado Supreme Court keeps high-earner tax hike on November ballot

Voters in Colorado will get to weigh in on a proposed income tax overhaul this November after the state Supreme Court dismissed a final legal challenge on Friday. The decision keeps Amendment 87 on the ballot, a measure that would increase taxes on the state's highest earners while reducing rates for those making less.

The court affirmed a lower court's ruling in a one-page order, stating it will issue a full opinion later. This move closes the door on an appeal filed by Michael Andre Hancock, an Arapahoe County resident. Hancock had sued Secretary of State Jena Griswold and proponents of the amendment in September, claiming the signature gathering process violated state rules.

The legal battle reached its peak just days before the election. A Denver judge rejected Hancock's effort to void the petition signatures on October 23. The Supreme Court's Friday decision upholds that lower court ruling, effectively allowing more than 130,000 signatures to stand.

Chris deGruy Kennedy, co-chair of Protect Colorado's Future, welcomed the ruling. He stated that Colorado courts have now confirmed that the signers deserve to have their voices counted. Kennedy acknowledged some administrative oversights during the registration of paid circulators but maintained that the campaign disclosed all details after submitting the petitions.

Kennedy criticized the legal challenge, describing it as an attempt by outside-funded lawyers to block voter choice. "The attempt by these dark-money-funded lawyers to say otherwise was a perversion of the law with one goal: deprive Colorado voters of the opportunity to vote on Amendment 87," he said in a prepared statement.

Jason Dunn, the attorney representing Hancock, expressed disappointment with the outcome. He argued the ruling leaves a system with little accountability for signature collectors who fail to follow rules. Secretary of State Jena Griswold praised the court's quick affirmation that the amendment was rightly certified to the ballot.

If passed, Amendment 87 would lower state income taxes for individuals and small businesses earning under $500,000 annually. Taxes would rise for those earning above that threshold through a graduated rate structure. Revenue generated would fund a new Colorado Futures Account for public education, healthcare, and early child care.

The measure is distinct from Proposition 136, which proposes a 4.4% tax cap. If voters approve both, the legislature or courts would need to resolve conflicts between the two measures, a process the 2026 Blue Book describes as having an unclear exact outcome.