2020 United States Senate election in Colorado

Gardner was elected to the U.S. Senate in 2014, narrowly defeating incumbent Democratic senator Mark Udall in a very successful election year for Republicans. Gardner was widely considered vulnerable in 2020 due to Colorado's recent Democratic trend and his support for Trump. Polling showed that more voters had a negative view of Gardner compared to a positive one. Gardner also faced a four-year grassroots campaign across the state by progressive political activists to hold him accountable for his votes, featured a cardboard cutout dubbed "Cardboard Cory". The seat was expected to be highly competitive and the most likely Republican-held seat to flip Democratic. The Democratic nominee, former governor John Hickenlooper, had a consistent double-digit lead over Gardner in the polls. Various minor scandals in the days leading up to the June 30 Democratic primary sparked speculation that Romanoff might win, but Hickenlooper had an advantage in name recognition, and harsh negative attacks by Romanoff reportedly led many state Democrats and voters to sour on him. ==Republican primary==

Candidates Nominee • Cory Gardner, incumbent U.S. senator Withdrawn • Margot Dupre, estate agent • Gail Prentice, veteran and business owner Endorsements Results ==Democratic primary==

Candidates Nominee • John Hickenlooper, former governor of Colorado and former candidate for president of the United States in 2020 Eliminated in primary • Andrew Romanoff, former Speaker of the Colorado House of Representatives, candidate for U.S. Senate in 2010, and nominee for Colorado's 6th congressional district in 2014 Withdrawn • Dan Baer, former executive director of the Colorado Department of Higher Education and former United States Ambassador to the Organization for Security and Cooperation in Europe (endorsed John Hickenlooper) • Derrick Blanton • Marcos Boyington, software engineer (endorsed Andrew Romanoff) • Denise Burgess, businesswoman and Denver Metro Chamber of Commerce board member • Ellen Burnes, Colorado State University professor and former chair of the Boulder County Democratic Party • Lorena Garcia, community organizer • David Goldfischer, associate professor at the Korbel School for International Studies at the University of Denver and national security advisor • Mike Johnston, former state senator and candidate for Governor of Colorado in 2018 • Danielle Kombo, medical recruiter and businesswoman (endorsed Stephany Rose Spaulding) • Dustin Leitzel, pharmacist • Alice Madden, former majority leader of the Colorado House of Representatives • Christopher Hawkins Critter Milton, 2020 Unity Party nominee for Colorado's 3rd congressional district • Keith Pottratz, technician and veteran (endorsed Lorena Garcia) • Stephany Rose Spaulding, professor at University of Colorado Colorado Springs and nominee for Colorado's 5th congressional district in 2018 (endorsed Lorena Garcia) • Erik Underwood, entrepreneur and candidate for Governor of Colorado in 2018 • John F. Walsh, former U.S. Attorney for the District of Colorado (endorsed John Hickenlooper) • Michelle Ferrigno Warren, nonprofit leader, immigration advocate • Angela Williams, state senator (ran for re-election) • Trish Zornio, biomedical scientist (endorsed John Hickenlooper) Declined • Diana DeGette, incumbent U.S. representative (ran for re-election) • Kerry Donovan, state senator (endorsed John Hickenlooper) • Crisanta Duran, former speaker of the Colorado House of Representatives ''(ran for Colorado's 1st congressional district, then withdrew)'' • Jena Griswold, Colorado Secretary of State • Cary Kennedy, former Colorado State Treasurer • Joe Neguse, incumbent U.S. representative for Colorado's 2nd congressional district (ran for re-election) • Ed Perlmutter, incumbent U.S. representative for Colorado's 7th congressional district (endorsed John Hickenlooper) • Joe Salazar, former state representative Caucus results Romanoff was the only candidate to get more than 30% in the initial precinct caucuses. Hickenlooper withdrew from the assembly process soon afterward, choosing to qualify for the ballot exclusively by petition. Ballot access for assembly candidates will be decided at the state assembly. Caucus winners do not always receive the party's nomination; Romanoff won them in the 2010 Democratic primary for Colorado's Senate race, but Michael Bennet won the party's nomination that year. The aggregate results of the various precinct caucuses on March 7, 2020, were: Results ==Other candidates==

Libertarian primary Nominee • Raymon Doane, Libertarian nominee for Colorado's 1st congressional district in 2018 Eliminated in primary • Gaylon Kent, author and perennial candidate Results Unity Party Nominee • Stephan "Chairman Seku" Evans, former candidate for mayor of Denver Eliminated at Unity Party convention • Joshua Rodriguez Withdrawn • Gary Swing, perennial candidate • Bruce Lohmiller (Green Party) • Joseph "Joey" Camp, performance artist (independent) • Marti Wolf (independent) ==General election==

Debate Predictions Post-primary endorsements Polling Graphical Summary Poll results with generic Democrat on whether Cory Gardner deserves to be re-elected with Generic Republican and Generic Democrat with Mike Johnston Results The election was not particularly close, with Hickenlooper winning by 9.32%. Hickenlooper's win was expected, as Colorado has moved more toward being a blue state. Key to Hickenlooper's victory was Denver County and its surrounding suburban counties, Adams, Arapahoe, Boulder, and Jefferson, the latter of which had been pivotal to Gardner's victory in 2014. Gardner did well in the typically red El Paso County, home of Colorado Springs. Gardner also did well in many rural areas of the state. However, Hickenlooper's strong performance in heavily populated counties proved too much for Gardner to overcome. Hickenlooper was also likely helped by Joe Biden, who won the state by 13.5%. Hickenlooper is the first senator from Colorado who was also the governor of Colorado since Senator Edwin Johnson was elected in 1936. Hickenlooper was sworn in as senator on January 3, 2021, for a six-year term that expires on January 3, 2027. By county Counties that flipped from Republican to Democratic • Chaffee (largest municipality: Salida) • Larimer (largest municipality: Fort Collins) Counties that flipped from Democratic to Republican • Alamosa (largest municipality: Alamosa) • Huerfano (largest municipality: Walsenburg) {{align|right| By congressional district Hickenlooper won four of seven congressional districts. ==See also==