The business fortunes of the Rs 2,500-crore M.A. Chidambaram group of companies (MAC), which includes fertiliser giant Southern Petrochemicals Industries Ltd (SPIC), is intrinsically intertwined with the political fortunes of the AIADMK. In 1991, when the AIADMK returned to power, the group's moving force—Chidambaram's son A.C. Muthiah—seemed invincible. Industry watchers predicted that an Ambani had finally arrived for the South.