California State Senator John Campbell won the Republican nomination by coming in first in the special primary election.

Other Republican candidates included dentist David R. Crouch, former Tustin councilman John Kelly, attorney Scott MacCabe, attorney Guy E. Mailly, real estate agent Masha A. Morris, businessman Marshall Samuel Sanders, businessman Edward A. Suppe, and physician Don A. Udall.

Attorney Steve Young, UCI professor John Graham (who ran for the seat in three previous elections against Chris Cox: 2000, 2002 and 2004), teacher Bea Foster, and marketing consultant Tom Pallow.

Campbell had the backing of many major Republican officeholders, including Governor Arnold Schwarzenegger, and closely identified with the policies of President George W. Bush.

Brewer was considered the more moderate alternative, in favor of abortion and stem cell research and endorsed by Senator John McCain.

The district is overwhelmingly conservative, with Republicans enjoying a 2 to 1 voter registration advantage (Christopher Cox won his last bid for re-election with 65% of the vote).

Democratic attorney Steve Young spent a large amount of his own money in the hope that Gilchrist and Campbell will split the conservative vote to a point which would allow him to edge both of them.

He faced the leading vote getter from the four other parties participating: American Independent Jim Gilchrist, Democrat Steve Young, Green Béa Tiritilli, and Libertarian Bruce Cohen in a December 6 runoff.