The American Israel Public Affairs Committee suffered a significant setback in Illinois' Ninth Congressional District, where Democratic voters rejected its heavy spending in a primary race. Daniel Biss defeated AIPAC-backed candidates despite the group pouring over $20 million through super PACs into four Illinois races. The loss came as Democrats increasingly oppose unconditional military aid to Israel.

Biss, a mayor and grandson of Holocaust survivors, made AIPAC's spending a central campaign issue. Internal polling showed 51% of Democratic voters viewed AIPAC unfavorably versus just 17% favorably. His victory highlighted growing progressive opposition to AIPAC's influence, with candidates like Zohran Mamdani winning in New York City and several Democrats refusing AIPAC contributions.

The defeat raises questions about AIPAC's $100 million midterm strategy as public opinion shifts on Israel. While the group helped elect allies in two other Illinois races, its inability to sway educated voters in key districts suggests traditional pro-Israel messaging may be losing effectiveness among Democrats.