Rick Santorum calls Barack Obama ` ` the worst president this country has ever seen '' Three of the four Republican presidential candidates debate Tuesday . They take aim at Obama ahead of the State of the Union debate . His strongest barbs , however , were aimed at Romney , the early front-runner in Florida who has seen Gingrich close the gap in recent days in polls . Mitt Romney presents his 2010 tax return .
Rick Santorum calls Barack Obama ` ` the worst president this country has ever seen '' Three of the four Republican presidential candidates debate Tuesday . They take aim at Obama ahead of the State of the Union debate . Mitt Romney presents his 2010 tax return .