What struck me about the first debates among 20 candidates for the Democratic nomination for president was how much they resembled a gaggle of graduate students. All seemed articulate and intelligent. All had a good grasp of the classroom material — in this case, the programs they were advocating or opposing. All were palpably ambitious, eager to show they were better suited than their rivals, without seeming too egotistical or ruthless. None, however, seemed “presidential.”