For the last three months, Rick Santorum and Newt Gingrich have been repeating the same argument against Mitt Romney: He’s a moderate, and a moderate Republican can’t win the White House. Naturally, given Gingrich’s stature as a historian, the critique dredges up memories of campaigns past. “We tried a moderate in 1996, and he couldn’t debate Bill Clinton effectively,” Gingrich said in January. “We tried a moderate in 2008. He couldn’t debate Barack Obama effectively and lost.” Santorum, too, has invoked the gruesome specters of Bob Dole and John McCain. “Look at the races in the last 30 years,” he chimed in last month. “[When] we nominated a moderate: McCain, Dole, Gerald Ford. When George [H.W.] Bush ran for re-election back in 1992 … [They] all lost.”