He graduated from George Nelson Tremper High School in 1979 and earned his bachelor's degree in political science from Kenosha's University of Wisconsin–Parkside in 1983.

[2] He was still working for the county executive when, in 1993, a chain of events—starting with the appointment of local-area congressman Les Aspin to join the cabinet of newly inaugurated President Bill Clinton—resulted in a vacancy in the Wisconsin State Assembly district in which Kreuser resided.

Despite strong support from a geographically diverse coalition of the assembly, Kreuser fell one or two votes short of Milwaukee representative Shirley Krug, who became the first female caucus leader in state history.

In March 2008 another opportunity presented itself to Kreuser when Kenosha County Executive Allan Kehl announced his intention to resign his seat after being indicted for accepting illegal payments.

Kreuser quickly jumped into the race, announcing his candidacy on March 25, 2008, and won the special election without opposition in June.