A turf war over a football team is developing between two Midwestern states with a long rivalry. Indiana has made a serious bid to lure the storied Chicago Bears across the border. The Bears want to leave Soldier Field, their home for 50 years. They previously proposed a $5 billion campus featuring a domed stadium in suburban Arlington Heights. But Indiana has a new law that would allow for financing and building a stadium in Hammond to lease to the Bears. Illinois lawmakers have responded with legislation that would give property and sales tax breaks to any so-called megaproject — such as a Bears stadium — of at least $100 million.