District 10’s Congressman Mark DeSaulnier seeks reelection in a district slightly altered after Proposition 50 passed. California’s 10th Congressional District is primarily located within Contra Costa country, while also encompassing a small portion of Alameda County, including Eastern portions of Dublin. DeSaulnier faces six contenders in the June 2 primary election.

Mark DeSaulnier

Mark DeSaulnier, a Democrat, has served as a U.S. Representative since 2015. His platform centers on lowering healthcare and housing costs, protecting Social Security and Medicare, reducing gun violence and improving local transportation and infrastructure. DeSaulnier sits on the House Committee of Ethics, Education and Workforce, and Transportation and Infrastructure. His legislative work includes measures to improve guardrail safety on federal highways and strengthen accountability for large public infrastructure projects like the Bay Bridge.

His endorsements include Speaker Emerita Nancy Pelosi, the Sierra Club, the United Professional Firefighters of Contra Costa County and the United Farm Workers of America.

Josh Hamilton

Josh Hamilton, a Democrat, is an entrepreneur and community organizer from Pleasant Hill.

His platform includes tax cuts for working people, universal healthcare with a $5 cap on prescription drug prices and massive federal investment in education. He calls for the establishment of a national investment fund that sends a yearly dividend payment to every adult citizen, based on a system already established in Alaska called the Alaska Permanent Fund Dividend. Hamilton frames his campaign around challenging systems that favor the powerful over everyday people and he describes his approach as evidence-based rather than ideological.

Mitchell Maisler

Mitchell Maisler, a Democrat, is a beer brewer from Walnut Creek.

Maisler’s platform includes calling for the abolition of ICE, ending corporate subsidies and establishing universal free healthcare funded by higher taxes on billionaires and corporations. He calls for reasonable and effective gun control, ending insider stock trading for lawmakers and investing in green infrastructure.

Bob Rowland

Bob Rowland, a Democrat, is a commercial land broker from Alamo with a background that spans military service, aviation and business.

Rowland says he entered the race because he is alarmed by what he views as a decline in the country’s fiscal, moral and ethical direction. In his voter guide statement, he said he is particularly troubled by the erosion of checks and balances and the rule of law, citing ICE raids as evidence of a government that no longer resembles the one he grew up in. He is running because he believes it is time for fresh voices and new ideas in the seat.

Jeffrey Frese

Jeffrey Frese, a Republican, is a small business owner from Moraga.

He is campaigning on making California more affordable by cutting federal red tape that he argues drives up housing, energy and food costs, and by reducing wildfire risk through improved federal land and forest management. He also supports ending Daylight Savings Time, implementing same-day voter registration with ID requirements, making Election Day a national holiday and enacting term limits. He favors an education system focused on literacy, math, critical thinking and practical workforce skills, including AI and automation. He calls for defending the constitutional right to travel.

Angela Griffiths

Dr. Angela Griffiths, a Republican, is a functional medicine practitioner and chiropractor from Castro Valley.

Griffiths’ platform focuses on strengthening families, improving affordability, protecting public safety, supporting healthcare transparency, increasing government accountability and protecting election integrity. On elections, she contends that California’s system has serious vulnerabilities, citing ballot harvesting practices, oversight gaps and poorly maintained voter rolls. She supports the federal SAVE Act as a remedy. On affordability, she argues that high wealth taxes and rising energy costs are pushing out middle-class families. She supports gender-affirming care for adults but opposes it for minors.

Her endorsements include the Contra Costa Republican Party, the Howard Jarvis Taxpayers Association and Stand for Health Freedom.

Katherine Piccinini

Katherine Piccinini, a Republican, is a retired businesswoman and longtime activist from Oakley.

Piccinini describes her campaign as putting people first, built around the values of God, family, life and country. She focuses on keeping manufacturing jobs in the U.S., elevating trade and apprenticeship programs to equal standing with four-year college degrees and reforming the tax code to reward marriage and parenthood. On governance, she supports term limits, a ban on congressional insider trading and cutting congressional pay if the budget goes unbalanced. She also opposes a central bank digital currency, calls for blocking foreign ownership of American farmland and homes, supports enforcing immigration laws and calls for protecting parental rights over school curriculum.

Her endorsements include California ProLife and Right to Life Federation, the California Rifle & Pistol Association PAC and the California College Republicans.