Colorado midterms become one of the costliest in U.S. history

National spending for the 2026 midterm elections is projected to approach $12 billion, a total that would make it the most expensive cycle in United States history. OpenSecrets, a non-partisan research group, reports that large portions of this capital are flowing into Colorado, where multiple races and ballot measures remain tightly contested.

Three congressional districts currently controlled by Republicans in Colorado are considered competitive. Democratic challengers are targeting these seats to help their party gain control of the U.S. House of Representatives. Both parties have contributed more than $40 million to these specific contests. One of these races ranks among the ten most expensive congressional elections of the year.

The eighth Congressional District, a Front Range area, stands as a primary target for Democrats. Incumbent Republican U.S. Rep. Gabe Evans has raised $7.13 million to defend his position. His Democratic opponent, Manny Rutinel, has collected $9.33 million according to campaign filings dated October 24. Seven other candidates in the race raised a combined $3.24 million. The district’s high cost of entry places it eighth among the nation’s priciest House races.

In the eastern part of the state, Democrat Eileen Laubacher is challenging incumbent Republican U.S. Rep. Lauren Boebert. Boebert moved to the district in 2024 to replace resigning Congressman Ken Buck. She left the 3rd Congressional District after nearly losing her seat in 2022, which was the closest U.S. House race in the country at that time. Laubacher has raised $13.61 million for her campaign. Boebert has raised $1.22 million.

The El Paso County district is the only congressional district in Colorado never held by a Democrat. The Cook Political Report designates this race as the state’s only toss-up election. Democratic challenger Jessica Killin has raised $5.55 million to unseat incumbent Republican U.S. Rep. Jeff Crank. Crank has raised $2.86 million for his defense.

Ballot measures in Colorado are also drawing substantial funding. Proposition NN, referred by the state legislature, would raise the limit on state tax revenue retained under TABOR. This change would increase K-12 education funding by 2% annually for the next decade. The measure is expected to add $4.6 billion in investment and reduce TABOR refunds. Support committees raised over $8.54 million as of October 14. Opposition committees raised nearly $3.81 million.

A separate measure would enact a graduated income tax rate. It would increase taxes on individuals and businesses with annual taxable income over $500,000 and lower taxes for those earning less. This proposal, driven by progressive advocates, survived multiple legal challenges, including one before the Colorado Supreme Court. Opposition committees raised nearly $6.91 million. Support committees raised $2.53 million.

Amendment 84 requires voters to verify their identity when submitting mail ballots. Proponents suggest writing the last four digits of a Social Security number or state ID number on the ballot. Local conservative politicians filed the measure, but out-of-state groups provide financial backing. Support committees raised $6.6 million. Opposition committees raised nearly $1.07 million.