Fair enough, DAT, but as you yourself point out, a woman's voice timbre or inflection automatically gets shrill when the volume goes up - as it most certainly did during the 3 or 4 rallies I heard snippets of.
Hillary, Palin, Thatcher. They all had/have the same problem - shrillness when they got loud. Thatcher took action to fix that, though I doubt she had problems with "valspeak".
Notice I said not one word about diction - the tonal inflections/accents associated with where a person originates. The use of the word "like" as a mental comma seems to be associated with young people, irrespective of locale. I used the term "valley girl" because that's where that kind of speech originated, AFAIK. My stepson, who goes to school in Austin, TX, speaks that way though he writes exceptionally well.
I pointed out that Palin would do well to be aware of that through vocal coaching. It can be reduced. That way she doesn't sound like somebody 25 years younger than she is.
YMMV.