Daniel Biss Wins Democratic Primary for Illinois’ 9th Congressional District

Evanston Mayor Daniel Biss won the Democratic primary for Illinois’ 9th congressional district on Tuesday, March 17, 2026, according to a race call by The Associated Press . He topped a crowded field of more than a dozen Democrats vying to succeed retiring Democratic Rep. Jan Schakowsky, who has held the seat since 1999 .

A Competitive Primary

The victory concludes a highly contested primary. Biss, 48, received endorsements from Schakowsky and Senator Elizabeth Warren . Throughout the campaign, he emphasized his experience in elected office and his commitment to progressive causes .

Key Challenger: Kat Abughazaleh

Political newcomer Kat Abughazaleh, 26, finished second to Biss, receiving approximately four percentage points less of the vote with over 90% of votes counted . Abughazaleh, a progressive researcher and commentator, ran on an anti-establishment platform, arguing that Democrats have not delivered sufficient results for voters . She proposed a focus on ensuring affordability of housing, groceries, and healthcare .

Role of Special Interest Groups

The primary was also marked by debate surrounding the influence of special interest groups, particularly pro-Israel groups like AIPAC. Individuals and groups aligned with AIPAC spent significantly on the race, attacking Biss and supporting state Senator Laura Fine . Biss, who is Jewish, publicly denounced AIPAC , but acknowledged a meeting with the group early in his campaign. He faced criticism for not clearly stating his position on U.S. Aid to Israel. Abughazaleh, who is Palestinian American, criticized Israel’s actions in Gaza .

Past of Daniel Biss

Prior to his mayoral role, Biss served in the Illinois House of Representatives from 2011 to 2013 and the Illinois Senate from 2013 to 2019 . Before entering politics, he was an assistant professor of mathematics at the University of Chicago from 2002 to 2008 . He ran unsuccessfully for the Illinois House in 2008 before being elected in 2010 . He also sought the Democratic nomination for Governor of Illinois in 2018, finishing second to JB Pritzker .

Campaign Controversy

During the campaign’s final days, Biss faced scrutiny following an accusation from a former student regarding an “inappropriate romantic relationship” . The Biss campaign acknowledged the relationship occurred in 2004, when Biss was a 26-year-old postdoctoral instructor and the student was 20, stating that Biss realized it was ill-advised and ended it .