[1] He was elected 43rd Lieutenant Governor of Illinois as Jim Edgar's running-mate, and served from January 14, 1991, to July 1, 1998, when he resigned to become president of Eastern Kentucky University.

He sought the Republican nomination for United States Senate in 1996 to succeed Paul Simon but was defeated in the primary by Illinois Representative Al Salvi.

Kustra before the primary was considered a heavy favorite to defeat Salvi, a relatively unknown conservative state representative, and Chicago area attorney.

From 2003 to 2018, he was president of Boise State University and is a member of the board of the Western Interstate Commission for Higher Education.

Congressman Raúl Labrador in August, 2017 suggested that it might be time for Kustra to leave Boise State University.