A California lawmaker ripped Rep. Duncan Hunter for relying on a “racist” campaign strategy by repeatedly describing his challenger, who has Palestinian heritage, as a “national security threat.”

Democrat Rep. Mike Levin called on the Hunter campaign to stop relying on anti-Muslim conspiracy theories to undercut his challenger in the 2020 race, Ammar Campa-Najjar.

“Both Campa-Najjar and Hunter were born in San Diego, and I believe that Hunter’s racist line of attack against a fellow American is beneath the office he holds,” said Levin, a first-term lawmaker who represents a neighboring Southern California district.

Democratic Rep. Susan Davis, who also represents a neighboring district in the California delegation, joined Levin. She called on Hunter, who beat Campa-Najjar in last year’s election despite being under indictment, to stop making false, Islamaphobic attacks.

“As a member of the House Armed Services Committee and someone who endorsed Ammar, I condemn these baseless attacks against him,” Davis said. “These kinds of attacks based on bigotry and fear have no place in any campaign.”

The race for Hunter’s 50th District became a national flashpoint last year when the Hunter campaign released an ad that used Campa-Najjar’s estranged father and grandfather to tie the challenger to the Palestine Liberation Organization’s attack at the Munich Summer Olympics in 1972. That attack happened 17 years before Campa-Najjar was born.

Davis, who is Jewish, noted that Campa-Najjar met with Jewish leaders to address this information about his family lineage, and passed background checks by the U.S. Federal Bureau of Investigation when he worked as an aide to the Obama administration.

The ads were widely decried as smearing Campa-Najjar, who is Christian and has Mexican and Palestian heritage.

But on Capitol Hill, neither then-Speaker Paul Ryan nor Minority Leader Nancy Pelosi condemned the attacks last year. Some pundits predicted the silence would give Hunter and other lawmakers a green light for further attacks.

In January, Campa-Najjar announced he would challenge Hunter for a second time in 2020.

Earlier this week, the Hunter sent out a fundraising email which accused Campa-Najjar of being boosted by “supporters” of the PLO, Politico reported.

Late Friday, Hunter campaign spokesman Michael Harrison did not back down, accusing Democrats of trying to paint Hunter as Islamophobic to distract the public from Campa-Najjar’s liberal views “that are woefully inconsistent with the 50th Congressional District.”

Harrison said Hunter’s endorsement last year of Republican Omar Qudrat in the 52nd District showed he was not Islamophobic.

In March, when Roll Call asked Harrison if the campaign was calling into question whether Campa-Najjar is loyal to the United States or the PLO, Harrison answered “no.”

Hunter defeated Campa-Najjar by less than 4 percentage points last year, after winning the 2016 election by 27 points. Inside Elections with Nathan L. Gonzales rates the race in 2020 lean Republican.

Hunter was stripped from committee responsibilities after being indicted last year on dozens of federal charges related to spending more than $250,000 in campaign funds on personal expenses such as family vacations and golf outings.

He faces trial in September.