When she first made it known that she wanted to be appointed to take over Mrs Clinton's seat, Miss Kennedy, 51, the daughter of the assassinated President John F. Kennedy, seemed a near certainty for the job.
But in the course of a few weeks she has alienated Governor David Paterson of New York, who has the sole power to make the appointment, and the American press, including the elite New York Times, which is a powerful influence on Democratic officials.
During an interview with the paper she stumbled badly, fuelling comparisons to Governor Sarah Palin of Alaska, whose bid for the vice-presidency was blighted by a series of disastrous interviews with Katie Couric of CBS News.
Perhaps most damaging of all was her repeated use of the phrase "you know", which she uttered 142 times and was left in the transcript when it appeared in print.
Explaining why she would be a good Senator, she said: "So I think in many ways, you know, we want to have all kinds of different voices, you know, representing us, and I think what I bring to it is, you know, my experience as a mother, as a woman, as a lawyer, you know, I've been an education activist for the last six years here, and, you know, I've written seven books – two on the Constitution, two on American politics.
"So obviously, you know, we have different strengths and weaknesses."
God Bless! May Caroline Kennedy's PR staffs do her some favors in the future interviews!