It has been generally acknowledged that in Sarah Palin's interviews with Charlie Gibson and Katie Couric, she has been inarticulate and given to non sequiturs. This is an anomaly. She has previously given good interviews and has a reputation as a good debater. What is happening here?
I approach this question as someone who has taught public speaking. My theory: she is displaying a phenomenon known as blocking.
Blocking occurs with some speakers when they delivering memorized material. In its typical manifestation, the speaker delivers a rush of words, has a barely perceptible pause, delivers another rush of words, pauses again, etc.
I use this metaphor to explain the phenomenon: it is like the olden days of computing when a computer read a long text file from a slow floppy disk and displays the text on the screen. Because of a slow floppy drive and slow CPU, the text comes up onto the screen chunk by chunk by chunk. This is what happens for some speakers when delivering memorized material. They speak more quickly than their brains can recall what to say next.
What is happening with Sarah Palin is a little different. Interviews place her in a confrontational situation. She is being challenged to explain certain prior statements. These statements are admittedly difficult to explain (e.g., justifying her foreign policy experience based on being able to see Russia from parts of Alaska, etc.).
At the same time, she has to keep in mind multiple rhetorical goals:
1. She is responding to the interviewer/inquisitor in front of her, trying to satisfy the interviewer in order to be able to move beyond the challenging question.
2. She is speaking to "undecided" voters whose decision hangs in the balance.
3. She is speaking to her base, wanting to keep this connection strong.
4. Unconsciously, she is trying to please her handlers -- the ones who have been coaching her and providing her talking points.
5. At the same time, she wants to portray her calm, collected, and charming personality.
Keeping all these audiences in mind is an incredibly difficult thing to do. Most politicians running national campaigns have developed this ability over decades. Gov. Palin has never before performed on the national stage. She could win her gubernatorial race speaking just to her fundamentalist base ecause there were two other candidates who split the mainstream vote.
As a result, Gov. Palin feels un-centered and off-balance. While her handlers have undoubtedly developed set pieces for her deliver in response to given questions, she is evidently not a good memorizer. (Some speakers are, but she is not). So being in a stressful place, she frantically tries to remember what she has been coached to say, but what comes up is a disjointed sequence of talking points. She is not good at weaving them together extemporaneously into a coherent paragraph.
Professionally speaking, I feel badly for her. I am convinced that left to her own devices, speaking on subjects with which she is thoroughly familiar, Sarah Palin is a gifted speaker. Ask her defend her position on "right to life" in a context in which she only needs to stroke a friendly crowd, and she will speak with strength and conviction. But on the national stage, opining on subjects that she does not know in depth, and doing all this in the midst of the conflict of a presidential election, she is unable to own her own strength.
Politically speaking, what Sen. McCain did to her turned out to be cruel. Sarah Palin is not ready for a national campaign.