BARSTOW The date has been set for the special election to fill the California Senate seat vacated by Michael Rubio, D-Bakersfield, three weeks ago.

The upcoming May 21 primary for the special election will not include Barstow voters although the elected senator will represent its residents.

"When somebody vacates their seat that was elected in 2010, we have to use the old precinct lines for voting," said Felisa Cardona, spokeswoman for the San Bernardino County Elections Office.

In 2011, California's district boundaries were redrawn according to updated census data, Cardona said. Thus District 16 was redrawn to include Barstow, but mostly encompasses voters in the southern Central Valley, including all of Kings County and parts of Fresno, Kern and Tulare counties. Voters in the newly formed District 16 can begin voting in the next regular election in 2014.

On Friday, California Governor Jerry Brown announced the special election date of July 23, and on Monday nominees could begin pulling nomination forms.

According to several published reports, former congressional nominee and Republican Andy Vidak said he was joining the race. John Estrada of Fresno and Francisco Ramirez Jr. of Riverdale have also filed for candidacy, according to a news report from the Visalia Times Delta.

The deadline to declare candidacy is March 29.

District 16 is one of three state senate seats to be filled this year in a special election. To regain a two-thirds supermajority, Senate Democrats will need to win back one of the seats. Rubio's resignation resulted in their losing the supermajority which allows them to pass tax changes and override vetoes.