Cory Gardner was born on August 22, 1974 in Yuma, Colorado, the son of Cindy L. (née Pagel) and John W. Gardner. His ancestry includes Irish, German, Austrian, and English. He graduated summa cum laude from Colorado State Universitywith a B.A. in political science in 1997. In college, Gardner switched from the Democratic Party to the Republican Party and interned at the Colorado State Capitol. He also studied abroad for a semester in Bremen, Germany, and is fluent in German. He went to law school at the University of Colorado to earn his Juris Doctor in 2001. Gardner served as General Counsel and Legislative Director for former U.S. Senator Wayne Allard of Colorado from 2002 to 2005.

Mark Udall was born in Tucson, Arizona to Patricia J. (née Emery) and Morris "Mo" Udall, the U.S. Representative for Arizona's 2nd congressional district from 1961 to 1991, and candidate for the 1976 Democratic nominee for President. Udall attended and graduated from Canyon del Oro High School in 1968. Udall graduated from Williams College in 1972. After college, Udall moved to Colorado and began his career with Outward Bound, a non-profit outdoor educationorganization.