CHICAGO – Progressives were facing their latest test Tuesday in Illinois, with a slew of candidates vying for a chance to help Democrats try to gain control of the U.S. House this fall. Enthusiasm already has been higher than usual among Democrats in the left-leaning state. In several districts currently held by Republican congressmen – areas where Democrats have sometimes struggled to field even one candidate – about a half-dozen Democrats are seeking the party’s nomination in Tuesday’s primary.