With Lisa Madigan choosing not to run again, the next attorney general can reinvent a job that has extraordinary potential to fight corruption and violent crime in a state with too much of both. Yet look who’s among the front-runners in the Democratic primary race for AG, according to a recent poll. Why, it’s Pat Quinn, who spent 12 of the past 15 years in Springfield as governor or lieutenant governor. And who years earlier was state treasurer. And years before that served in Cook County government.