Sen. Barack ObamaBarack Hussein ObamaThe Hill's Campaign Report: Gloves off in South Carolina 6 ways the primary fight is toughening up Democrats for the fall general election Bloomberg called Social Security a 'Ponzi scheme' as mayor MORE (D-Ill.) began airing this presidential campaign ad in Iowa today. In it, Obama talks to a group of seniors about Social Security, saying the country needs an honest discussion to fix spending and revenue problems as the baby boomer generation retires.