The Illinois 9th congressional district's strong Democratic lean, reflected in its D+19 Partisan Voter Index and consistent margins exceeding 30 points in recent cycles, underpins trader consensus favoring Daniel Biss at 96.8%. The open seat following longtime Representative Jan Schakowsky's retirement drew a crowded Democratic primary that Biss won in March 2026, while Republican nominee John Elleson emerged from a smaller field. Recent candidate forums have highlighted divides on immigration enforcement and local affordability without shifting the race into competitive territory. Models and nonpartisan ratings classify the contest as safe or solid Democratic, with Biss's prior state legislative and mayoral experience adding to the implied probability. A late scandal, health event, or unusually large national Republican swing could still alter the outcome before November 3.