Colorado voters close in on historic tax shifts

Colorado voters appeared poised to enact the state's most extensive tax code overhaul in 34 years on Tuesday, as preliminary results showed a split decision among three competing ballot measures.

Amendment 87, which proposes a graduated income tax, held a slim lead in the early count. At 10 p.m., 50.6% of voters supported the measure while 49.4% opposed it. Because the amendment repeals rather than amends constitutional language, it requires only a simple majority to pass.

The proposal would raise corporate and individual income tax rates to 7.4% for income above $500,000, with a gradual increase to 8.4% for earnings over $1 million. These higher rates would apply to the top 3% of earners. The remaining 97% of Coloradans earning under $500,000 per year would see a slight reduction in their income tax.

Nonpartisan state legislative staff estimated the measure would generate $2 billion in additional revenue by the 2027-28 fiscal year.

A separate measure, Proposition NN, which raises the state's constitutionally mandated revenue cap, was tracking for passage with 55% support against 45% opposition. State analysts projected this change would allow the state to retain approximately $500 million more in annual revenue. The measure would likely eliminate TABOR refunds, which are returned to taxpayers when the revenue cap is exceeded, for the foreseeable future.

Proposition 136, a conservative countermeasure backed by the group Advance Colorado, faced an uphill battle. The proposal aimed to block Amendment 87 by capping the state income tax rate at 4.4%. It stood at 47% support, short of the majority needed to pass. If both Amendment 87 and Proposition 136 had passed, the measure with the higher yes vote total would have determined the final tax structure.