The McCain campaign is protecting Sarah Palin from questions the way the Secret Service protects the president from bullets.
From the pool report account of what happened after McCain and Palin's meeting with Georgian President Mikheil Saakashvilli and Ukrainian President Viktor Yushchenko:
McCain then looked around the room and gestured as if to welcome questions. The AP reporter shouted a question at Gov. Palin ("Governor, what have you learned from your meetings?") but McCain aide Brooke Buchanan intervened and shepherded everybody out of the room.
Palin looked surprised, leaned over to McCain and asked him a question, to which your pooler thinks he shook his head as if to say "No."