In 1948, Thornton was elected to the Colorado State Senate, a position that he held for only two years before becoming governor.

As governor, he was instrumental in developing the U.S. Air Force Academy in Colorado Springs.

Dwight D. Eisenhower, like Thornton Texas-born, instead chose Richard Nixon, a freshman U.S. senator from California.

He was the Republican nominee for the U.S. Senate in Colorado that year, but was narrowly defeated by the Democrat John A.

[3] Dan Thornton died of a heart attack in Carmel, California, on January 18, 1976, two weeks shy of his 65th birthday.