Democratic challenger Derek Tran adds to his lead over California GOP Rep. Michelle Steel

Derek Tran added a little to his lead in the race for California’s 45th congressional district over Rep. Michelle Steel on Saturday in one of the closest House of Representatives contests in the nation.

Tran, a Democrat and Orange-based attorney, increased his advantage to 545 votes, up from 519 votes on Friday over Steel, R-Seal Beach. Saturday’s total only included an update from Orange County; Los Angeles County will resume providing updates Tuesday.

In central Orange County, the district includes Westminster, Garden Grove, Cypress, Buena Park and parts of Brea, Fullerton and Yorba Linda. It also includes a small portion of Los Angeles County, covering Artesia, Cerritos and Hawaiian Gardens.