Cisneros, a Democrat since 2008, previously served as Under Secretary of Defense for Personnel and Readiness in the Biden administration and the U.S. representative for California's 39th congressional district from 2019 to 2021.

In April 2021, he was nominated by President Biden to serve as Under Secretary of Defense for Personnel and Readiness, and after confirmation by the Senate, he assumed office on August 24, 2021.

On September 18, he announced his candidacy for California's 31st congressional district[5][6] and defeated Republican Daniel Martinez in the 2024 election.

[8] His mother worked in a cafeteria, while his father served in the Vietnam War and suffered from exposure to Agent Orange.

[12] He and his wife became philanthropists, establishing endowments for scholarships to be given to Latino students at GWU and the University of Southern California.

They also founded Generation First Degree Pico Rivera, with the goal of ensuring every Latino household in Pico Rivera has at least one college graduate, and the Gilbert and Jacki Cisneros Foundation with an initial investment of $20 million to provide mentorship in education.

[13][17] He specifically cited Royce's vote to repeal the 2010 Patient Protection and Affordable Care Act, also known as Obamacare, as a reason he chose to run.

[9] They own a home in Pico Rivera,[31] and lived in Newport Beach until they moved to Yorba Linda in late 2017, the year he began running for election.