The AP describes McCain as irritable and sarcastic, partially as a result of this exchange:

Meeting Tuesday with the editorial board of The Des Moines Register, McCain was asked why he picked the Alaska governor, someone “who doesn’t have a lot of experience.”

“Thank you, but I disagree with your fundamental principle that she doesn’t have the experience,” McCain replied before citing Palin’s work as a PTA member, city council member, mayor and governor. “You and I just have a fundamental disagreement, and I am so happy the American people seem to be siding with me.”

When it was suggested that Palin’s lack of experience worried voters, McCain turned sarcastic.

“Really? I haven’t detected that in the polls, I haven’t detected that among the base,” he said. “If there’s a Georgetown cocktail party person who, quote, calls himself a conservative who doesn’t like her, good luck. I don’t dismiss him. I think the American people have overwhelmingly shown their approval.”

Ever been to a Georgetown cocktail party? He definitely wasn’t being sarcastic.