When negotiating, sometimes it is necessary to get up and start walking out the door. Sometimes the act of doing that will elicit a response that could not be gotten any other way.
For the technique to work, it's necessary that the person one is negotiating with believe the intention to walk out the door is sincere. Since many conservatives aren't very good at faking such things, the only way to have their actions look sincere is for them to be sincere.
Show ONE piece of evidence that the folks who said they wouldn't vote for McCain were the reason he picked Palin.