Democratic primary:

—Trisha Calvarese, a union advocate and National Science Foundation writer who lives in Highlands Ranch. She won top-line billing at the district’s Democratic assembly.

—Ike McCorkle, a Marine veteran who lives in Parker and lost to Buck in the 2022 and 2020 elections.

—John Padora, a Severance resident who has worked as a manufacturing engineer and machinist.

Note: On the same day as the primary, the 4th District also will have a special election — featuring Calvarese and Republican Greg Lopez — to fill the the seat for the rest of Buck’s term this year.

5th Congressional District

(Covers most of El Paso County, including Colorado Springs and its suburbs)

Republican primary: Colorado’s third open-seat GOP primary comes about as a result of longtime Rep. Doug Lamborn’s decision to step down after his ninth term ends in January. Two candidates have made the ballot:

—Jeff Crank, a political consultant and longtime radio host in Colorado Springs.

—Dave Williams, the Colorado Republican Party’s chairman and a former state representative. He secured top-line billing at the district’s GOP assembly.

Democratic primary:

—River Gassen, a research scientist and graduate student. She secured top-line billing at the district’s Democratic assembly.

—Joe Reagan, an Army veteran and nonprofit executive.

6th Congressional District

(Includes Aurora and many of Denver’s southern suburbs)

Democratic primary: U.S. Rep. Jason Crow, an Aurora resident who has held the seat since 2019, is running unopposed.

Republican primary: John Fabbricatore, a former director of the Denver field office of U.S. Immigration and Customs Enforcement who lives in Aurora, is unopposed.

7th Congressional District

(Includes metro Denver’s Broomfield and Jefferson counties and extends south to Park, Fremont and Custer counties)

Democratic primary: U.S. Rep. Brittany Pettersen, a former state lawmaker from Lakewood who has held the seat since 2023, is unopposed.

Republican primary: Sergei Matveyuk, who lives in Golden and owns a business that appraises and repairs art and antiques, is unopposed.

8th Congressional District

(Includes several north Denver suburbs and Greeley)

Democratic primary: U.S. Rep. Yadira Caraveo, a Thornton pediatrician who won one of Colorado’s most competitive races in 2022, is unopposed.

Republican primary:

—Gabe Evans, a state representative from Fort Lupton who is an Army veteran and former police officer. He won top-line billing at the district’s GOP assembly.

—Janak Joshi, a former state representative from Colorado Springs who now lives in Thornton and is a retired physician.

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