The law is projected to reduce Medicaid spending by more than $900 billion through 2034. It includes stricter eligibility rules and twice-yearly checks, with work or community-engagement requirements for some adults scheduled to take effect after the midterm elections.

Ulises Hernandez, a 41-year-old Bakersfield resident who has relied on Medicaid for years, said the prospect of tighter rules worries him. After a dental crown slipped down his throat during a procedure in September, he said, he waited eight hours in an emergency room and went more than two days without food.

Hernandez later joined a protest outside Valadao’s Bakersfield office. He said he plans to vote for Democratic challenger Randy Villegas, arguing that the law could make it harder for families to get care.

Valadao has rejected the description of the law as a Medicaid cut. During an Oct. 6 televised debate, he said the requirements were reasonable and that he had helped negotiate provisions allowing community activities such as job training or volunteering to count toward them.

The stakes extend beyond Medicaid. The Center for American Progress, a left-leaning policy organization, estimates that about 60,000 more people in the district could lose coverage by 2034 as a result of the law and the expiration of enhanced Affordable Care Act premium tax credits. The group estimates more than 2 million Californians could lose coverage statewide, with the state losing about $30 billion a year in federal funding.

Valadao’s district has long been politically competitive. Democrats have held a double-digit voter-registration advantage since he first won his seat in 2012, but he has won six of his seven House elections. He lost in 2018, when Democrats made his votes to repeal the Affordable Care Act and his ties to then-President Donald Trump central issues.

The district’s boundaries were redrawn last year amid a national redistricting fight, leaving Valadao with a seat considered more favorable to Democrats. Jeffrey Cummins, a political science professor at California State University, Fresno, said Valadao has previously won over some moderate Democratic voters by focusing on water, agriculture and other local concerns. The new voter mix and dissatisfaction with incumbents could make the race more difficult, he said.

Villegas, a political science professor and former school board member, has made health care a core part of his campaign. He backs a single-payer system and has accused Valadao of supporting a law that will take coverage from Valley families. Valadao, who has also emphasized water and agricultural issues, called Villegas’ criticism a distortion of the truth at a September campaign event.

Health care costs remain a major voter concern nationally. A September KFF poll found voters trusted Democrats over Republicans on health care by a 2-to-1 margin. The contest is also attracting substantial campaign spending: Republicans and Democrats each booked more than $16 million in advertising in the district through Election Day, according to AdImpact data.

The Nov. 3 election will test whether Valadao can again hold a district where many households rely on Medicaid, or whether the law’s potential effects on coverage help Villegas win a seat Democrats see as a path toward control of Congress.