Millions in ‘Dark Money’ Spent to Influence Colorado Voters

This story by Chase Woodruff appeared on Colorado Newsline on October 27, 2026.

Colorado’s most expensive ballot-measure showdown in the 2026 midterms is an overlapping series of fights over several high-stakes tax questions, with a mishmash of left- and right-leaning groups spending a combined total of more than $14 million to influence Colorado voters on the measures ahead of Election Day.

Among the dozens of issue committees registered to support or oppose the 14 measures appearing on the 2026 statewide ballot, none is better-funded than Yes for Kids Colorado, a teachers-union-funded group that has spent more than $6.8 million to support Proposition NN.

That measure, referred to the ballot by the Legislature, would increase funding for K-12 education by about $500 million a year by raising the state’s constitutionally-mandated revenue growth cap. Most of Yes for Kids Colorado’s funding comes from the National Education Association.

The Protect Colorado’s Future Coalition, meanwhile, has spent a little less than $2 million to support Amendment 87, a proposal to establish a graduated state income tax. The coalition’s top donors include philanthropist Merle Chambers; Colorado WINS, the state employees’ union; and progressive advocacy groups like the Bell Policy Center and the Colorado Fiscal Institute.

Two conservative issue committees, Brighter Colorado and Let’s Go Colorado, are registered in opposition to both Amendment 87 and Proposition NN. Brighter Colorado has received more than $2.6 million in funding from donors including Advance Colorado, a conservative “dark money” group that does not disclose its donors; the Republican-affiliated group GOPAC; and Common Sense America, a separate dark-money group based in Maryland. Let’s Go Colorado is funded entirely by the Denver Metro Chamber of Commerce.

Brighter Colorado is also registered in support of six other Colorado ballot measures backed by Advance Colorado, including Proposition 136, which aims to neutralize Amendment 87 by setting a cap on state income tax rates. Issue committees aren’t required to separate their expenditures for different ballot measures in the disclosure reports they file with the Colorado secretary of state’s office.

Another group, Don’t Price Us Out, has reported spending just under $2 million to oppose Amendment 87 only, most of which came from the dark-money American Prosperity Coalition, according to campaign finance disclosures. An issue committee affiliated with Americans for Prosperity, the network founded by conservative megadonor Charles Koch, has also spent $350,000 to oppose Amendment 87.

Statewide, more than $47 million had been spent on issue campaigns in Colorado in 2026 — a figure that includes dozens of campaigns at the local level, as well as spending on some statewide campaigns, like a Democratic-backed redistricting proposal or an effort to increase state funding for roads, that were withdrawn or blocked from the ballot. The total spending puts the state on pace to see more money spent on ballot measures this year than in any election since 2020.

Millions backing Proposition 137
Colorado’s most lopsided 2026 ballot contest involves Proposition 137, which would boost state funding for conservation and wildfire mitigation projects by exempting tax revenue from sporting goods sales from constitutional limits set by the Taxpayer’s Bill of Rights.

A campaign in support of the measure reported spending more than $5 million through Oct. 14. Most of the campaign’s funding comes from two environmental groups, The Nature Conservancy and Western Resource Advocates.

Some grassroots environmental groups are critical of the measure and its funding for wildfire mitigation, which can involve “fuel reduction” projects that they say harm forest ecosystems. A campaign opposing Proposition 137 has reported $6,295 in expenditures, mostly on digital advertising.

Dark-money voter ID push
Spending figures for most of the rest of the 14 measures appearing on Colorado’s 2026 ballot show either proponents or the opposition with a major financial advantage.

More than $5.7 million in dark money has been spent to convince voters to back Amendment 84, which would require Colorado voters to provide the last four digits of their Social Security number or driver’s license number, in addition to their signature, to ensure their mail ballot is counted.

The sources of that money are entirely undisclosed. The Colorado Voter Trust Initiative, the committee supporting Amendment 84, has received all of its funding from four entities: the Texas-based American Prosperity Caucus, which contributed $2.4 million; the Coalition for American Prosperity and Growth, which contributed $2.2 million and is based in Colorado Springs; and the American Jobs and Growth Fund and A Public Voice, two Virginia-based groups that gave $1 million each. None of the four groups has a public presence, and all four list their addresses as P.O. boxes.

Defend Our Ballots, an issue committee registered to oppose Amendment 84, reported spending $75,000 as of Oct. 14. Its largest donor is a Denver-based dark-money nonprofit of the same name. Vote Common Sense, a committee funded by a wide range of left-leaning advocacy groups, has also spent $130,112 to oppose a slate of nine conservative ballot measures than includes Amendment 84.

Opposition to anti-trans measures
Protect Kids Colorado, a conservative group backing a pair of ballot measures targeting the transgender community, has reported just under $400,000 in expenditures since it launched its campaigns last year. Proposition 134 aims to prevent transgender children from participating in school sports, while Proposition 135 would prohibit health care professionals from knowingly performing any surgery on a minor “for the purpose of altering biological sex characteristics.”

The group’s top donors include a dark-money nonprofit also named Protect Kids Colorado, which has contributed about 60% of its funding; brewing scion Jeff Coors; and two groups associated with far-right Woodland Park pastor Andrew Wommack, the Truth and Liberty Coalition and Andrew Wommack Ministries.

Families Not Politics, the campaign opposing Propositions 134 and 135, has outspent Protect Kids Colorado by a 5-to-1 margin since it was registered in February. The group has received funding from liberal advocacy groups including LGBTQ+ rights organization One Colorado; reproductive rights groups Cobalt and Planned Parenthood; and the American Civil Liberties Union.