SACRAMENTO, Calif. (AP) — California Gov. Gavin Newsom on Thursday set a special election in Los Angeles County to replace state Sen. Holly Mitchell, who left in mid-term for the county board of supervisors.

The special primary election will be March 2. If no candidate wins more than half the vote, a special runoff election will take place May 4.

Mitchell's departure temporarily leaves the Senate with 30 Democrats and nine Republicans.

The 30th Senate District is the most heavily Democratic district in the state, according to the California Target Book, which tracks legislative races. Just 7% are registered Republican, 23% decline to state, and 65% Democratic. 

It includes central and western Los Angeles County, including Culver City, Ladera Heights, View Park, and West Athens, and the Los Angeles neighborhoods of Downtown, South Los Angeles, Crenshaw, Mid-City, Century City, Cheviot Hills, and Mar Vista.

Mitchell is endorsing as her successor Assemblywoman Sydney Kamlager, who once was Mitchell’s district director, according to the Target Book. A victory by Kamlager would set up a chain-reaction special election to fill her Assembly seat.

Two Democrats, Culver City councilman Daniel Lee and former state Board of Equalization member Jerome Horton, have formed campaign committees, as has Republican Renita Duncan, a sergeant major in the U.S. Army Reserves. Democrat Cheryl Turner, a trial lawyer who ran for Horton's open seat two years ago, filed a statement of intention.

The district includes the center of Los Angeles’ Black community and has the largest African-American voting population in the state, yet Latinos make up a majority of the district's population, according to the Target Book. But the number of eligible Latino voters has been relatively small.