Democrat Lucille Roybal - Allard , who has represented the 40th district since 2013 and previously represented the 34th district from 2003 to 2013 and the 33rd district from 1993 to 2003 , is running for reelection .
Democrat Lucille Roybal - Allard , who has represented the 40th district since 2013 and previously represented the 34th district from 2003 to 2013 and the 33rd district from 1993 to 2003 , won reelection . 
 Democrat Mark Takano , who has represented the 41st district since 2013 , is running for reelection .