2006 United States Senate election in California

The 2006 United States Senate election in California was held November 7, 2006. Incumbent Democratic U.S. Senator Dianne Feinstein won re-election to her third full term.

Feinstein stood against Republican Dick Mountjoy, who had never held a statewide elected position, but had been a state senator for several years. Also running was Libertarian Michael Metti, Don Grundmann of the American Independent Party, Todd Chretien of the Green Party and Marsha Feinland of the Peace and Freedom Party.

Because California is a state that requires a large amount of money to wage a competitive statewide campaign, it is not unusual - as was the case for this race - for a popular incumbent to have no significant opponent. Several prominent Republicans, such as Bill Jones, Matt Fong, and others, declined to run, and a previously announced challenger, businessman Bill Mundell, withdrew his declaration after determining he would not be a self-funded candidate (as Michael Huffington was in the 1994 election). As of 2024, this is the most recent U.S. Senate election in California where both major party nominees have since died.

Primaries
Link to primary results

Democratic Party

 * Dianne Feinstein, incumbent U.S. Senator, former Mayor of San Francisco

Lost in primary
 * Martin Luther Church, retired program manager
 * Colleen Fernald, artist and entrepreneur

Republican Party

 * Richard Mountjoy, former State Senator, former State Assemblyman and candidate for Lieutenant Governor in 1998

American Independent Party

 * Don J. Grundmann, chiropractor

Green Party

 * Todd Chretien, writer

Lost in primary
 * Tian Harter, green activist and a 1992 Congressional nominee
 * Kent Mesplay, environmental activist, air quality inspector, and candidate for President in 2004

Libertarian Party

 * Michael Metti, businessman and perennial candidate

Peace and Freedom Party

 * Marsha Feinland, state party chair, socialist activist, and retired teacher

Controversy
On September 22, the Los Angeles Times reported that Mountjoy's official biography, as found on his campaign website, falsely asserted that he had served aboard the battleship USS Missouri during the Korean War—he had actually served aboard the heavy cruiser USS Bremerton. A review of the ships' logs corroborated this and the website was quickly changed to reflect his service aboard the Bremerton rather than the Missouri. "I think it was just something that somebody picked up, it didn't come from me."

- Richard Mountjoy

Results
Feinstein won the election easily. She won almost every major populated area, winning in Los Angeles, San Francisco, Sacramento, and San Diego. Feinstein was projected the winner as soon as the polls closed at 11 P.M. EST.

Results breakdown
Final results from the Secretary of State of California.

Counties that flipped from Republican to Democratic

 * Butte (largest city: Chico)
 * Del Norte (largest community: Crescent City)
 * Mono (largest municipality: Mammoth Lakes)
 * Nevada (largest town: Truckee)
 * San Luis Obispo (largest town: San Luis Obispo)
 * Trinity (largest community: Weaverville)

Counties that flipped from Democratic to Republican

 * Kings (largest municipality: Hanford)