Daniel Biss holds a commanding lead in the Illinois 9th congressional district race due to the area's consistent Democratic lean, reflected in double-digit margins in recent presidential and House contests. As the Democratic nominee and Evanston mayor, Biss secured his party's nomination in the March 2026 primary against a crowded field and benefits from the open-seat dynamic following longtime incumbent Jan Schakowsky's retirement. Republican nominee John Elleson, an Arlington Heights pastor who won his primary, faces structural disadvantages in a district rated Solid or Safe Democratic by multiple forecasters. Candidate forums have highlighted differences on immigration enforcement and local development issues, yet these have not altered the district's underlying partisan baseline. Late developments such as national economic shifts or unforeseen candidate events could narrow the gap, though historical patterns and current positioning limit realistic paths for an upset.