
In the 2024 House race for CA-31, Gil Cisneros (D) defeated Daniel Jose Bocic Martinez (R) 59.7% to 40.3%. Gil Cisneros received 148,095 votes compared to 99,856 for Daniel Jose Bocic Martinez, a comfortable 19.5-point margin indicating a moderately safe district.
This was an open-seat race with no incumbent running — Grace F. Napolitano (D) previously held the seat. Open seats typically attract stronger candidates and heavier spending from both parties. The 2024 presidential election drove higher voter turnout, which can help or hurt down-ballot candidates depending on the top of the ticket.
In the 2018 House race for CA-39, Gil Cisneros (D) defeated Young Kim (R) 51.6% to 48.4%. Gil Cisneros received 252,004 votes compared to 236,782 for Young Kim, a narrow 3.1-point margin that would have flipped with a small shift in turnout or persuasion.
This race flipped the seat from Republican to Democrat. Edward R. Royce (R) held the seat previously but either retired or lost in a primary. Party flips at the seat level are relatively rare and often signal shifting district dynamics. As a Democrat, Gil Cisneros benefited from the historical midterm penalty against the president's party — with a Republican in the White House, the opposition typically gains seats.