Buck, who lost a senate bid to Michael BennetMichael BennetSenate passes college anti-Semitism bill Speculation and starting points: accreditation, a new administration and a new Congress The untold stories of the 2016 battle for the Senate MORE (D-Colo.) in 2010, will seek to unseat Colorado’s other incumbent senator, Mark UdallMark UdallGardner's chief of staff tapped for Senate GOP campaign director The untold stories of the 2016 battle for the Senate Colorado GOP Senate race to unseat Dem incumbent is wide open MORE (D-Colo.), in 2014.
According to the Denver Post, Buck will launch his campaign and tour the state in early September.
Buck, a district attorney, joins state Sens. Randy Baumgardner and Owen Hill in seeking the Republican nomination.
In 2010, political watchers believed Bennet, who was appointed by then-Gov. Bill Ritter (D) in 2009 to fill the seat left by Ken Salazar (D), who became secretary of the Interior, was vulnerable to a Republican challenger in a year that a wave election gave the GOP a majority in the House.
But Bennet squeaked out a victory over Buck, whose campaign was plagued by controversial comments. Buck believes global warming is a hoax, and at one point appeared to liken homosexuality to alcoholism.