TPM explains the Palin effect

Everything fits the narrative now: Most Independents are driven away. Intellectual conservatives like Republican-leaning newspapers, Andrew Sullivan, Colin Powell, David Brooks, Christopher Buckley, David Frum, and yours truly have concluded that Palin is unacceptable. Whether we like Obama or not, the salient point is that we simply cannot vote for McCain-Palin. (Though Frum, being an NROite, still has to support McCain)

The people left supporting Palin are:

1) The Base that will always vote Republican. This includes strictly anti-choice, anti-condom Dobsonites, Iraq war lovers, etc.
2) Republican officials due to party loyalty or being invested in having another Republican presidency or needing her coattails for re-election
3) Republican hacks in the conservative media like NRO, Rush Limbaugh, Hugh Hewitt...

There are very few PUMAs left, so that's mostly it. And it's not enough to win.