I think socially moderate Ace of Spades nails it here:
And as I always note: Yes, that’s true, but liberal men were just as aghast at this performance. Sarah Palin committed two crimes that night: She spoke of Obama as if he were not, in fact, an earthbound god, but an unqualifed, shady pretender, a figure not ripe for worship but for lampooning; and therefore she threatened the chances of a liberal winning the White House.
It has to be remembered that before her speech, Obama won every poll, easily; it was no an election so much as a coronation. After that speech, at least for two weeks, McCain/Palin surged ahead of Obama/Biden; she scared the s*it out of them. I still think that when they see Sarah Palin, she reminds them of those weeks of terror, the same way you’ll always be reminded of a death if you see the person responsible for it. It’s emotionally wrenching just to be reminded that for three weeks in September and October of 2008, A God Bled.