“The president is eager for the next debate, and he’ll be passionate and energetic in describing how far we’ve come as a country in the last four years,” said Stephanie Cutter, Mr. Obama’s deputy campaign manager. “Part of what last night showed is that the facts and the truth matter, and the president will make sure they matter next week as well.”

Mr. Biden’s wide grin and energetic demeanor prompted cheers from Democrats who had been desperate for the kind of in-your-face political rumble that Mr. Obama did not deliver a week ago…

Mark Salter, a senior adviser to Senator John McCain’s presidential campaign in 2008, quipped on his Facebook page: “Evidently, the Obama campaign debate strategy is sleepy cop/crystal meth cop.”