Newt Gingrich ditched his "high road" campaign Tuesday, calling Mitt Romney a liar as the presidential contest shifted to upcoming contests in New Hampshire, South Carolina and Florida. A PAC supporting Mr. Romney has been running anti-Gingrich ads. (Associated Press)

Newt Gingrich ditched his "high road" campaign Tuesday, calling Mitt Romney a liar as the presidential contest shifted to upcoming contests in New Hampshire, South Carolina and Florida. A PAC supporting Mr. Romney has been running anti-Gingrich ads. (Associated Press)