SPRINGFIELD — Cracks are beginning to show in Michael J. Madigan’s hold over the House Democratic caucus that he has led as Speaker for all but two years since 1983.Three more members of that caucus called for Madigan to resign this week, at least as House Speaker and chair of the state’s Democratic Party. They join another Democratic representative and three senators — all women — and a number of high-profile Republicans in calling for Madigan’s resignation from at least one of his leadership positions.A Madigan …