He was a California State Assemblyman from 1996–2002, Assembly Republican Leader from 2000–2001, and a member of the Orange County Board of Supervisors from 2003–2013.

After initially working as an engineer, Campbell and his wife founded BIMA Corporation, a company that specialized in Taco Bell franchises.

In 1996, Campbell was elected to the represent eastern Orange County's 71st District in the State Assembly with 71% of the vote.

In 2002, Orange County Supervisor Todd Spitzer won 73% of the vote to replace the term-limited Campbell.

Campbell, in turn, won 75% of the vote in the 2003 special election to fill the vacancy on the Board of Supervisors left when Spitzer resigned to become an Assemblyman.