In fall 2018, longtime former State Rep. Lou Lang, D-Skokie, received a phone call from Mike McClain, who had spent decades lobbying for electric utility Commonwealth Edison after 10 years in the General Assembly.McClain was delivering a message from House Speaker Michael Madigan, who was worried Lang was becoming a liability to his Democratic caucus — a liability the now-former speaker would rather not deal with after the year he’d already had.Earlier in 2018, a former campaign staffer publicly accused Madigan …