But Fong had already qualified to run for Assembly, and state law bars a candidate from withdrawing after last Friday’s filing deadline. He decided to forge ahead, regardless, filing his candidacy with Kern County election officials, and McCarthy swiftly endorsed him. One of his competitors, far-right conservative David Giglio, threatened to sue if Fong remained on the ballot.

The open seat in a deep-red swath of the Central Valley attracted a number of other hopefuls, including Tulare County Sheriff Michael Boudreaux and Kyle Kirkland, a Fresno casino magnate.

After a week of uncertainty, the office of Secretary of State Shirley Weber confirmed that California election law prohibits Fong from running for Congress.

“The Secretary of State’s office has determined that Mr. Fong’s filed nomination papers for Congressional District 20 were improperly submitted,” it said in a statement. “Mr. Fong will not appear on the list of certified candidates for Congressional District 20 that our office will transmit to county election officials on candidates on December 28.”

Fong said he will not stand down, and his campaign blasted Weber’s move as “an unprecedented interference in the candidate filing process.” The campaign said it planned to challenge the decision in court.

“Voters in the 20th Congressional District have a right to choose the candidate of their choice to represent them in Congress,” Fong said in a statement. “I will fight the Secretary of State’s misguided decision and do whatever it takes to give voters in our community a real choice in this election because the voters choose our elected officials, not Sacramento.”