Judged in a vacuum, last night was probably Mitt Romney’s weakest debate performance so far. He let both Rick Santorum and Rick Perry throw him off his normally measured, calm, and reassuring delivery. But judged next to the other contenders, Romney, again, looked like the most presidential candidate on the stage.

Early on Herman Cain failed to respond adequately to every other candidate’s contention that his 9-9-9 plan amounted to a tax hike on the vast majority of the American people. Perry looked small and petty when he repeatedly attacked Romney personally over some illegal immigrants a former Romney contractor had hired. The crowd let the initial exchange go, but when Perry pressed the issue again, there were loud boos from the audience.