In November 2020, Garnett's colleagues elected him to serve as speaker of the Colorado House of Representatives for the two-year term beginning in January 2021.

[2] Prior to taking office, Garnett was the executive director of the Colorado Democratic Party.

[3] In 2010 Garnett managed the political campaign of his father, who ran for Colorado attorney general that year.

[4] Garnett was elected to his seat in 2014 with 72.6% of the vote against Republican Party opponent Jon Roberts.

[2] Garnett's father, Stan, is the former district attorney for Boulder County, Colorado.