The San Diego Union-Tribune published a front-page story on Thursday examining Ammar Campa-Najjar’s family history, noting that the Democrat’s grandfather was not merely a member of a terrorist organization, but a leader.

Muhammad Yousef al-Najjar — also known by his nom de guerre, Abu Youssef — was involved in the massacre of eleven Israeli athletes at the 1972 Olympic Games in Munich, Germany. The Union-Tribune article notes that there is debate among historians “about the level of involvement of al-Najjar.” Campa-Najjar highlighted that facet of the article on Twitter on Thursday evening to suggest that the Union-Tribune had somehow debunked the overall story.

He also rejected his grandfather’s actions regarding Munich “if he was involved,” the article quotes him as saying.

In fact, the article by Charles T. Clark confirms that Campa-Najjar’s grandfather was no mere bit player. He was a co-founder of Yasser Arafat’s political party, Fatah, which still controls the Palestinian Authority. At the time, the Palestine Liberation Organization (PLO) was recognized as a terrorist organization; Fatah is still involved in terror.

Clark writes:

Campa-Najjar’s grandfather, Muhammad Yusuf al-Najjar, was a leader in the Fatah political party, which was and remains today one of the largest factions of the Palestine Liberation Organization.

Al-Najjar helped found the party alongside Yasser Arafat — the former longtime leader of the PLO — while the two were Palestinian refugees working in Kuwait in 1965, according to news reports.

That may explain the campaign donation that Campa-Najjar received from a Palestinian ambassador last year, who serves as the deputy chief of the Palestinian mission at the U.N. Campa-Najjar has refused to return the donation.

The Union-Tribune has endorsed Campa-Najjar against his opponent in the 50th congressional district, incumbent Duncan Hunter, who is under indictment for charges of misusing campaign funds. He has declared his innocence.

Read the full Union-Tribune article here.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.