Candidate · Colorado · Republican

Mark Baisley

Candidate for U.S. Senate from Colorado (2026)

Mark Baisley is a Republican member of the Colorado Senate from Woodland Park, representing District 4, and an aerospace engineer who leads the software firm Slipglass Inc. He is the Republican nominee for U.S. Senate from Colorado in 2026, having been the only Republican on the June 30, 2026 primary ballot, and faces incumbent Democratic Sen. John Hickenlooper on November 3.

Background

Biography

Mark Baisley was born in 1955 in Hastings, Minnesota, and holds a Bachelor of Science from Columbia College. He spent about 40 years in information technology focused on aerospace, defense, education and financial services, working at NASA, Hughes, Raytheon and Martin Marietta, and is president of Slipglass Inc., an engineering software firm. He chaired the Douglas County Republican Party and served as vice chairman of the Colorado Republican Party. He was first elected to the Colorado House of Representatives in 2018 and ran for the state Senate in 2022; he represents Senate District 4, covering Chaffee, Custer, Douglas, Fremont, Jefferson, Lake, Park and Teller counties, from Woodland Park. He entered the 2026 Republican primary for governor and on January 5, 2026, announced he was leaving that race to run for the U.S. Senate seat held by Democrat John Hickenlooper. He was the only Republican listed on the June 30, 2026 primary ballot for U.S. Senator and faces Hickenlooper on November 3.

Voting record

This office does not cast congressional roll-call votes.

Candidate for U.S. Senate from Colorado (2026) is an executive office. The Baseline will not manufacture a congressional voting score for it; sourced checks, statements, and coverage appear below.

The Baseline desk

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When The Baseline verifies and publishes a check on a claim by Mark Baisley, it will appear here with its evidence and primary sources. An empty record is not a rating.

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Candidate · Colorado · Republican

Mark Baisley

Candidate for U.S. Senate from Colorado (2026)

Background

Biography

Voting record

This office does not cast congressional roll-call votes.

Candidate for U.S. Senate from Colorado (2026) is an executive office. The Baseline will not manufacture a congressional voting score for it; sourced checks, statements, and coverage appear below.

The Baseline desk

Published claim checks

Claim checks are reviewed editorial work. They are separate from the voting-data summaries above.

No published checks yet

When The Baseline verifies and publishes a check on a claim by Mark Baisley, it will appear here with its evidence and primary sources. An empty record is not a rating.

Biography

This office does not cast congressional roll-call votes.

Published claim checks

Also from Colorado

Biography

This office does not cast congressional roll-call votes.

Published claim checks

Also from Colorado