Stan Honda / AFP / Getty Images New York Senator Hillary Clinton

Fell off the tough-shrill balance beam onto the "shrill" side  with a THUD. More defensive than usual, and at times too political and too hot tempered. Borderline disastrous moment at the end when she gave an equivocal answer about drivers licenses for illegal immigrants in New York; it opened the door for her opponents to pounce by turning it into a character issue  and pounce they did. The failure of her performance was cumulative, however, so only those watching the whole debate would see how weak her evening was. If she loses the nomination, tonight will go down in history as the first step to her defeat  no fatal "Dean Scream" catastrophe, but far from her finest moment, to say the least.

by Mark Halperin

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