The latest McCain gaffe has to do with him declining to meet with the Prime Minister of Spain and his campaign, in attempting to rescue him, saying that Spain is an adversary. Many are saying that his reference to Latin America while responding to a question about Mr. Zapatero, and doing so twice, reflects a lack of foreign policy expertise. I suspect that he simply wasn't listening to the question, and that he wasn't listening to the followup question either.
If you watch his body language at town halls you can see that John McCain, after hearing the first few words of any question, is no longer listening to the questioner but is already formulating his answer. He radiates impatience for the questioner to finish so that he can begin speaking. The main reason for that is that he never actually answers questions, he pulls out stump speeches in response to questions, so as soon as he has heard enough of the question to know which stump speech he needs he's done listening and is ready to go.
In the Spanish Gaffe case above he didn't listen long enough and pulled out the wrong stump speech and then, after not listening to the followup question, he merely repeated the initial stump speech.
The same thing happened when the lady asked the question which included her opinion that we needed to reinstate the draft. The film clip that I saw did not include the early part of her lengthy question, but when the clip started McCain was already clearly impatient for her to finish. Each time she paused to draw a breath he started to speak to cut her off, and he visibly was not listening to her. He had turned away from her and was bringing his microphone up to his mouth when she said the bit about the draft, and I have no doubt that he simply never heard it before he said that he agreed with everything that she had said.
I don't know about you, but to me answering questions which you did not bother to listen to is a terribly dangerous trait for our President.