Colorado voters will decide this November whether to fundamentally change the state’s tax system, moving from a flat income tax to a graduated one under Amendment 87. This measure, if approved, would reduce state income taxes for an estimated 97% of Coloradans, while increasing revenue from higher-income residents to support critical services like education, childcare, and healthcare. However, critics argue the proposal could hinder the state's economic competitiveness and raise questions about the long-term implications of embedding such a system in the state constitution.
The proposed change was a central topic at a recent discussion hosted by the University of Denver’s Scrivner Institute of Public Policy. The panel, moderated by DU assistant professor of public policy Stefan Chavaz-Norgaard, included Democratic state Rep. Lorena Garcia and Colorado Politics chief legislative reporter Marianne Goodland.
Under Amendment 87, taxpayers earning less than approximately $511,000 annually would see their state income taxes decrease. Those above this threshold would pay more. Colorado is currently one of 15 states with a flat individual income tax rate, set at 4.4%. This year, voters will also consider Proposition 136, a separate ballot measure that asks to maintain the existing 4.4% flat rate.
Rep. Garcia, who is also CEO of the Colorado Statewide Parent Coalition, spoke in favor of Amendment 87, highlighting the strain on existing state systems. She pointed to the high cost of childcare, which can range from $1,200 to $2,700 per month for families, noting that the state’s current childcare subsidy system serves only a fraction of eligible families. Garcia also criticized teacher compensation, stating that Colorado’s education system cannot continue to rely on teachers needing additional jobs to make ends meet. She argued the state is in an "absolute perfect storm," needing more revenue while also re-evaluating current spending. The Protect Colorado’s Future Coalition, a group of over 30 organizations, supports Amendment 87 and has raised about $1.5 million for the campaign, according to Goodland.
Opponents of Amendment 87 contend the proposal could diminish Colorado’s economic appeal. They also question the wisdom of amending the state constitution to create a tax system where income thresholds do not automatically adjust for inflation, potentially pushing taxpayers into higher brackets over time even if their income increases only due to inflation. Garcia dismissed this particular concern, stating it is unlikely to affect many Coloradans in the near term because relatively few people earn more than $500,000. Critics also suggest that higher taxes could prompt affluent residents and businesses to move or invest elsewhere, particularly as Colorado vies with states offering lower costs. They believe the measure could worsen existing concerns about the state’s affordability and its regulatory environment for businesses. Supporters, however, counter that there is insufficient evidence to suggest a graduated income tax would lead to significant migration of wealthy residents or corporations.
Further complicating the November ballot, Goodland informed attendees that Amendment 87 faces a legal challenge concerning the validity of the petition signatures used to qualify it for the ballot. The campaign submitted around 130,000 signatures, just over the required minimum of 124,632. A lawsuit disputes about 9,000 signatures, alleging issues with petition circulators’ training certifications. Goodland stated that if these 9,000 signatures are disqualified, the measure could fall below the necessary threshold and potentially be removed from the ballot, even after votes are counted. Garcia, however, disputed this argument, contending that signatures should be invalidated based on the voter's qualification, not solely on issues involving the circulator.
The possibility of voters approving both Amendment 87 and Proposition 136 creates a unique scenario, as these measures present conflicting approaches to the state’s income tax. Panelists at the DU discussion disagreed on what would happen if both passed, with one possibility being that courts would need to decide which measure to implement. This uncertainty highlights a central complexity of Colorado’s ballot system, where constitutional provisions, statutory tax restrictions, and voter-approved measures can overlap and potentially require judicial interpretation.
Amendment 87 also interacts with Colorado’s Taxpayer’s Bill of Rights, or TABOR. Under the proposal, revenue up to the amount projected in the state’s official ballot analysis would be exempt from the TABOR spending cap. Any revenue exceeding these projections would be subject to the state’s existing rebate requirements. Voters will also consider Proposition NN, another ballot question that would allow certain revenue, otherwise returned to taxpayers under TABOR, to be spent on education and childcare for a decade.
An audience member at the discussion raised a concern about local school districts, specifically Denver Public Schools, potentially misusing education funds or allocating them more towards administrative salaries. Garcia partially agreed with the sentiment and advised the voter to be more vocal and pressure local school boards.
Ultimately, supporters of Amendment 87 argue that the additional revenue is essential to prevent cuts to schools, childcare programs, and health care services, especially as other parts of the state budget face increasing pressure. Opponents face a more fundamental question: whether amending the state constitution to establish a new graduated tax system is the right approach, and whether higher taxes on top earners will ultimately strengthen or weaken Colorado’s economy. With several overlapping questions about taxes, spending, and TABOR on the ballot, voters face a complex decision this November.
