Ammar Campa-Najjar, a candidate for office in California’s 50th Congressional District, won an overwhelming endorsement on Sunday from the California Democratic Party, which brushed aside a potentially inflammatory report in the Israeli press about his paternal grandfather, who was a mastermind of the terrorist attack at the 1972 Munich Olympics.

Campa-Najjar is running a progressive, grassroots campaign that relies on small donors and an army of volunteers. He had earlier won what’s called a pre-endorsement, which requires at least 70 percent of the local delegates to win. He won the statewide endorsement easily, pulling 97 percent, despite the presence of a well-funded challenger, veteran Josh Butner, who has the backing of the New Democratic Coalition, the pro-Wall Street wing of the party.

Campa-Najjar said he was moved by the party’s continued support. “I’m deeply moved by the hundreds of people — both old friends and new faces — who have come to my support. People who rather than seek to politicize the situation, have humanized it by offering anecdotes from their own lives,” Campa-Najjar told The Intercept. “A lot of people have said, ‘We have family like that, too.’”

At the California Democratic Party convention over the weekend, the delegates approved the slate of candidates who had won their local endorsements. The state party endorsement raises the profile of candidates, which can help boost fundraising and comes with a coveted spot on the party mailer. Campa-Najjar is already the best funded Democrat in the race, with more than half a million dollars raised so far.

Last Tuesday, the Israeli newspaper Haaretz ran an article titled, “Grandson of Munich Massacre Terrorist is Running for Office — Sounding a Peaceful Tone on Israel.” Campa-Najjar’s paternal grandfather, Muhammad Yusuf al-Najjar, was a senior member of Black September, a Palestinian terror organization that carried out several attacks against Israelis in the 1970s, including the massacre of 11 athletes at the Munich Olympics. Israeli commandos assassinated al-Najjar and his wife in 1973, 16 years before Campa-Najjar was born.

In the days following the Haaretz report, the news of Campa-Najjar’s lineage was picked up by the local press, including the San Diego Union-Tribune, the Times of San Diego, and East County Magazine. The Times of Israel and the Jerusalem Post also joined in the coverage.

The 28-year-old candidate, who was born in Southern California to a Palestinian father and Mexican mother, responded to Haaretz last week by condemning his grandfather’s actions. “As an American citizen living in the 21st century, I will never be able to understand or condone the actions and motivations of my grandfather,” he said.

Though his platform is much more focused on domestic issues that directly impact his potential constituency, his Palestinian heritage has put him in the unique position of having to express nuanced views on the Israeli-Palestinian conflict and Middle East peace, an expectation few candidates must meet. The four policy issues he lists on his campaign website are jobs, immigration, healthcare, and gun safety, offering progressive proposals such as Medicare for all.

Under California’s primary system, the top two vote-getters in the June 5 primary will advance to the general election, regardless of party affiliation. The other serious contenders in the race are Butner and the Republican incumbent Duncan Hunter. Butner is also supported by Massachusetts Rep. Seth Moulton, who has raised hundreds of thousands of dollars for military veterans running for Congress around the country.

While Campa-Najjar had brought in $520,155 by the end of December — about a third of it raised in a fourth-quarter surge — Butner had raised $422,799, according to campaign finance reports. Hunter, meanwhile, had raised $461,118. Another Republican in the race, Shamus Sayed, had brought in $185,539. Though Sayed trails in fundraising, a split among Democratic voters could have the effect of two Republicans advancing to the general election.

Still, even with the state party’s endorsement of Campa-Najjar, Butner shows no sign of backing down.

“I am not surprised that I did not win a process created by politicians and party insiders,” Butner wrote on Facebook. “I will continue to fight to put the interests of our country and our community over party politics.”