CHICAGO — Evanston Mayor Daniel Biss won Tuesday’s Democratic primary to succeed Rep. Jan Schakowsky, dealing a blow to the American Israel Public Affairs Committee in a race that had turned into a referendum on the group’s ability to influence the party.

Biss, whose mother is Israeli and whose grandparents are Holocaust survivors, has sharply criticized Israel’s war in Gaza — and faced an onslaught of attack ads from a group aligned with AIPAC as a result.

He defeated a crowded field that included social media influencer Kat Abughazaleh, a Palestinian American who is a more vocal critic, as well as AIPAC’s preferred candidate, state Sen. Laura Fine. Biss is now favored to win the general election in the heavily Democratic district.

The race had become one of the country’s most closely watched Democratic primaries, in large part because of AIPAC’s involvement in a district whose population is more than 10 percent Jewish and which has had a Jewish representative for more than 60 years.

An AIPAC-aligned group spent more than $5 million dollars in ads to boost Fine and attack Biss, then later, Abughazaleh. That group pulled down its anti-Biss attacks at the end of the race, before a different shell PAC emerged to prop up another low-polling progressive in the race in an attempt to divide the progressive vote.

Biss, meanwhile, had the endorsement of the more liberal pro-Israel organization J Street and publicly slammed AIPAC’s interference in Democratic primaries.

He is a former University of Chicago math professor who also served in the Illinois House and Senate and lost the 2018 Democratic gubernatorial primary to current Gov. JB Pritzker.

Schakowsky, the 14‑term incumbent who announced her retirement last year, formally backed Biss in January, praising his legislative experience and alignment with her priorities (they share similar views on Israel as well as other issues). That endorsement, coupled with his deep roots in the district, helped Biss fend off the crowded field and negative attacks.

Throughout the campaign, Biss pitched a broad policy platform that included boosting federal investment in affordable housing, expanding Social Security benefits and banning stock trading by members of Congress. He also drew national attention last year for his confrontations with federal immigration enforcement agents at a local gas station and his presence at anti‑ICE protests.