Incumbent Mike Thompson (D) and Eric Jones (D) are running in the general election for California's 4th Congressional District on November 3, 2026.

The Press Democrat's Phil Barber wrote, "[T]he 4th District race has become a clash of identity: a young, politically unproven candidate taking on an establishment politician aiming for his 15th term in the House of Representatives." The Sacramento Bee's Mathew Miranda wrote, "[Thompson] has emphasized gun violence prevention, fiscal responsibility and health care while in Congress ... [Jones] has focused on reaching disaffected voters, particularly younger demographics, whom he says both major political parties have lost hold of in recent years."

Thompson was elected to the House in 1998. He served in the California Senate from 1990 to 1998. A Thompson campaign ad said, "Like dogs in obedience school, Donald Trump has trained Washington politicians to sit and roll over. Not Mike Thompson. He's stood up to Trump from day one." U.S. Sens. Adam Schiff (D) and Alex Padilla (D) and House Minority Leader Hakeem Jeffries (D-N.Y.) endorsed Thompson.

Jones is the founder of the American Dream Institute and a former partner at Dragoneer Investment Group. Jones' campaign website says, "We deserve a government that works to improve our lives and better our future — not one that enriches itself and protects the power of its career politicians and megacorporations." Our Revolution endorsed Jones.

The election is taking place in the context of redistricting that changed the district's boundaries from those used in 2024. CalMatters' Maya C. Miller wrote, "The new 4th Congressional District includes more conservative parts of Colusa, Placer, Sacramento, Sutter and Yuba counties, many of whose voters were previously represented by the late Republican Rep. Doug LaMalfa and his successor, Rep. James Gallagher."

In the top-two primary, Thompson placed first with 41.0% of the vote and Jones received 22.2%. Six Republican candidates received a combined 36.1% of the vote and one independent candidate received 0.7%.

The outcome of this race will affect the partisan balance of the U.S. House of Representatives in the 120th Congress. All 435 U.S. House districts are up for election.

Currently, Republicans have a 219-214 majority with two vacancies in the U.S. House.