David Cohen is a scientist, educator, and civic leader who has represented District 4 on the San José City Council since January 2021. A lifelong public servant with deep roots in the communities he represents, Cohen brings an unusually rigorous, data-driven perspective to local government — shaped by over two decades as a professional engineer and fourteen years of elected leadership on a local school board.
Cohen was born in La Jolla, California, and earned a bachelor's degree in chemical engineering from Cornell University in 1990, followed by a Ph.D. in chemical engineering from UC Berkeley in 1996. While studying at Cornell during the 1988 presidential election, he volunteered with a "Get Out the Vote" campaign and says he officially "caught the bug" for politics. After completing his doctorate, he began his engineering career, first working as a process development engineer at Clorox before moving to Silicon Valley, where he spent over two decades as an engineering manager at Lam Research. He holds 10 patents and has published several papers and given numerous talks at technical conferences.
Cohen moved to San José's District 4 in the late 1990s after finishing his doctorate, was appointed to the San José Public Library Commission in 2000, and started a family with his wife a few years later. He spent 14 years as a member of the Berryessa Union School District Board, where he focused on building strong relationships with local families, teachers, staff, and students. He helped the district weather a protracted recession and worked to ensure students had access to technology, mental health services, and educational resources. Among his accomplishments, he helped the district launch a dual-immersion Mandarin program, protected class sizes, preserved music and science programs, retained counselors, and added social workers to each school site. He also served six years on the San José Library Commission, advocating for longer library hours and helping open new branches.
Cohen assumed office on January 1, 2021, after defeating incumbent Lan Diep in the November 2020 general election. His election was described by local news as a realignment of the business-labor split on the City Council, though Cohen himself has expressed a desire to govern collaboratively across ideological lines rather than simply flipping the council's partisan balance. He won reelection outright in the March 2024 primary, with his current term running through December 31, 2028.
Since joining the council, Cohen has worked to open North San José to development, push the city toward carbon neutrality by 2030, improve constituent services, plant more trees, and strengthen parks and library services. District 4 is one of San José's most geographically diverse districts, stretching from the marshlands of Alviso along the Bay to the dense tech corridors of North San José and the residential neighborhoods of Berryessa.
Cohen is now running for the California State Senate in District 10, seeking to bring his record of local leadership to Sacramento with a focus on public safety, housing, education, environmental stewardship, and protecting immigrant families. He is a Senior Fellow of the American Leadership Forum and a member of the San José Downtown Rotary. He lives in the Berryessa neighborhood with his wife, two children, and an assortment of pets.
