Colorado’s $3.6M Dark Money Campaign Targets Flat Tax Amendment

Steamboat Springs —Millions in undisclosed “dark money” are flooding Colorado’s November election to kill Amendment 87. The fight is over whether the state keeps its flat income tax or moves to a graduated system.

The numbers skew heavily against the proposal. Supporters of Amendment 87 disclosed roughly $1 million in spending by the Oct. 6 filing deadline. That money came from small donations — between $5 and $500 — from about 300 individual residents, plus contributions from dozens of local and state nonprofits.

The opposition spent more than $3.6 million. Read that again. More than three times the amount the supporters raised. The difference matters. The opposition’s war chest wasn’t built on small checks from everyday voters. Filings show only a couple dozen individual donations from Coloradans. The rest came from large gifts by groups that don’t have to reveal who is paying.

Ian Silverii, with the Protect Colorado’s Future Coalition, called the funding structure “outrageous.” He argued that wealthy donors are trying to keep billionaire and corporate tax rates locked at the same level as the rest of us.

The mechanism behind the secrecy is the 501(c)(4) organization. These are conservative political advocacy groups that operate as nonprofits. Because they are 501(c)(4)s, they are exempt from donor disclosure rules. That allows big money to flow into the campaign without the public knowing exactly where it came from.

Advance Colorado is the primary vehicle for this spending. The group was founded in 2020 by former Republican Gov. Bill Owen. It leads the charge against Amendment 87. Like the other groups, it does not disclose its donors. However, reporting from the Denver Post and other outlets has identified billionaire Phil Anschutz as a major backer.

The stakes are high because Amendment 87 would fundamentally change how Coloradans pay taxes. The measure proposes replacing the current flat tax with a graduated system. Under the plan, anyone making less than $500,000 would see their taxes lowered. Those earning more than $500,000 would face higher rates. Proponents claim this shift would raise an additional $2.7 billion for the state. That revenue would go toward healthcare, education, and childcare.

It’s not just a one-on-one fight. The opposition is also pushing Proposition 136. This measure aims to maintain Colorado’s flat tax rate of 4.4%. It acts as a direct countermeasure to Amendment 87. If both measures pass, it could create legal questions that courts would have to answer.

Kristi Burton Brown, Advance Colorado’s executive vice president, tried to deflect the criticism. She said voters should focus on what the policy does, not who funds it. But when the funding comes from groups that hide their donors, the question of influence is hard to ignore.

The short version: Amendment 87 wants to lower taxes for most people and raise them for the wealthy. The opposition wants to keep the flat tax. And they have the money to make their case heard. Whether that spending sways the vote is something we’ll find out in November.