A federal judge has struck down a key provision of a 2016 Colorado ballot initiative, finding it places an undue burden on political parties seeking to close their primary elections to unaffiliated voters. The ruling represents a win for the Colorado Republican Party, which had challenged the law.

Ruling Details and First Amendment Concerns

U.S. District Court Judge Philip A. Brimmer, based in Denver, determined that the law violates the First Amendment’s protections of freedom of association. The law requires a three-quarters vote from a party’s central committee to close its primary, a threshold Brimmer deemed unconstitutionally high.

The Three-Quarters Threshold

Judge Brimmer noted the origin of the three-fourths requirement is unclear, stating it’s “an unusual and difficult barrier” more akin to amending a constitution than regulating political parties. He did not establish a new threshold for closing primaries, nor did he provide specific guidance for implementation.

Background of the Lawsuit

The lawsuit was initially filed in 2023 by the state GOP under the leadership of Dave Williams, who criticized the 2016 ballot initiative, known as Proposition 108, as a “radical leftwing” effort. Williams argued closing primaries was essential for protecting Republican candidates.

The case continued after Williams’ departure and nearly outlasted current GOP chairwoman Brita Horn, who is stepping down later this month. Judge Brimmer previously denied a request to immediately close primaries for the 2024 election cycle.

Impact on Colorado Primaries

Since Proposition 108’s passage, the number of unaffiliated voters in Colorado has steadily increased. No party has successfully opted out of the state’s semi-open primaries under the current rules. However, the Republican party has attempted to close its primaries at least three times, most recently in September 2023, falling short of the required threshold with 64% support.

Unaffiliated Voter Participation

In 2018, approximately 100,000 unaffiliated voters participated in Republican primaries. This number more than doubled to 231,000 by 2022, representing 37.1% of ballots cast in those contests. In some counties, unaffiliated voters equaled or surpassed the number of Republican voters in recent primaries.

The ruling applies to both the Republican and Democratic parties, should the Democrats choose to close their primaries in the future. Representatives from both parties and the Secretary of State’s office, Jena Griswold, have not yet issued comments on the ruling.