Like I said before, I don't think waterboarding is torture. Our Marines go through more rigorous treatment during basic training. There are certain means of intimidation allowed by the Geneva Convention that don't rise to the level of "torture" (sleep deprivation, exposure to cold, etc.)
And as Richard Lowry said on the PBS News Hour a few weeks ago, a number of journalists have volunteered to have waterboarding done to them. If it were truly "torture", journalists would not be volunteering for the treatment. As Lowry said, journalists wouldn't be saying "Gee, can you rip out one of my fingernails, I'd really like to know how that feels..."
(And I also saw a journalist interviewed who volunteered to be waterboarded several times, interviewed just a week ago on CNN with Anderson Cooper, with video shown of the procedure.)
It's a typical liberal stance, condemning your own nation for abstractions of principle on piddly matters, while the enemy saws off people's heads, and these same liberals call them "freedom fighters".
McCain doesn't think it's a piddly matter.