“I remember back when he was mayor he would deliver a two-hour budget presentation without any notes, and do it flawlessly,” Giuliani biographer Andrew Kirtzman told NBC News. “One of the things that was so impressive was his extraordinary grasp of facts.”

“That kind of precision that he was famous for is missing,” he added. “His inability to stay disciplined with the facts, that has been the biggest surprise to me.”

Paul Moses, who covered Giuliani for Newsday, echoed Kirtzman.

“He came in as mayor and mastered the details of city government very quickly. He knew the law, he knew where he could push it, and he took advantage of that,” Moses said. “He just seems very imprecise now, constantly waffling and changing, and certainly that would not have been characteristic of him in the past.”