I’ve always found Obama to be a maddening candidate. Time after time, he has raced ahead of Hillary--and then failed to put her away. First, he ran up impressive fundraising numbers, and then neglected to catapult ahead of Clinton. Then, he gave an excellent Jefferson-Jackson Day speech, but hesitated and didn’t deliver a devastating blow. These failures raised questions about his ultimate electability in my mind. He always produced an excellent first act, but never followed that with a compelling second act. Did his high-minded rhetoric handcuff him? Could he get nasty when it counted? Why was his performance so uneven?

Tonight answered those questions. When it counted, he stuffed Hillary. He upped his rhetoric in the final days of the campaign, and certainly on caucus night. His speech was stunningly good--strutting, broad in its appeal, prime time in every respect. With his performance among independents, he has won the argument over electibility. At least, I have no idea how Hillary can now portray herself as a better general election candidate. (That's not to say that Obama doesn't have real weaknesses as a candidate.) In fact, I honestly don’t know if she has another hand to play. I can't think of one at this late hour. And I would imagine that for undecided voters--like myself--tonight will prove incredibly influential.

--Frank Foer