SPRINGFIELD — A final argument to the state’s top court hoping to salvage a proposed amendment on legislative redistricting has honed in on one element of a Cook County judge’s ruling last month.Cook County Circuit Judge Diane Joan Larsen declared the ballot question unconstitutional, in part, because it requires state high court judges to declare political ties — a new constitutional prerequisite for justices.Citizen-driven changes to the constitution can only change aspects of the legislature.But …