Saturday’s Illinois Derby at Hawthorne Race Course, a Grade 3 event and the signature race on the track’s calendar, was not included in Churchill Downs’ new Road to the Kentucky Derby qualifying series this spring, a dismissal that generated much debate among Triple Crown followers. This caused Hawthorne officials to reschedule and re-market the 1 1/8-mile Illinois Derby as a prep for the May 18 Preakness Stakes, and based on Saturday’s result, that plan seemed ingenious in hindsight. Departing emerged as one of the most talented members of his age group based on his 3 1/4-length romp at Hawthorne, and could pose a serious threat to the Kentucky Derby winner if both show up in Baltimore.