Has his attitude in general changed since that innocent summer that capped the previous millennium? There's nothing to indicate that that's the case. Despite his pinched jocularity with the credulous dupes of the political media, McCain is one of the more notoriously ill-tempered members of the Senate, engaging in vitriolic, profane tirades with colleagues who displease him. He sings "Bomb Iran" to the tune of Barbara Ann at campaign rallies as if it's funny; he speaks with eerily measured certainty of more -- and presumably better -- wars. Where is not important, nor is why. That will be decided at the post-election pitch meeting, when disinformation and no-bid contracts will be outlined for the political wing of the WGA.
Back to McCain supposedly being exempt from his use of racial slurs. Look, no one questions what he endured (well, a few do -- check out the comments, with one guy accusing McCain of cooperating and collaborating with his tormentors, but for the sake of argument, we're talking about mostly rational people), but no one dares to dig, dares to follow up, dares to question the received and accepted orthodoxy.
Why was McCain captured and tortured? Because he was shot down while bombing villages, as part of an invasion that was not known for bothering to discriminate combatants from civilians. Hell, we've kept hundreds of people -- many of them simply handed over for reward money by this or that warlord -- for half a decade bound and blinfolded in Guantanamo, with no charges, no lawyers, no recourse, no end in sight. It's not daily beatings and bone-breakings, and starvation and terror, but it ain't pleasant either. It's certainly not constitutional.
What exactly is the purpose of torture? In the case of the current American use, it is notionally a program of "enhanced interrogation" techniques, designed to break the person's psyche rather than his body, and take advantage of that weakened state. The discrepancy between knowledgeable people who say this is materially useless and politically very counterproductive, versus the few who insist (but are strangely unable to corroborate) that actual lives have been saved with sensory deprivation, refrigerated cells, forced painful positions for extended periods of time, and ear-shattering volumes of rap or metal, is on a par with other notable "controversies" such as global warming or intelligent design.
It doesn't "work" because that's not what torture is meant to do. It's meant (like racial slurs) to dehumanize the victim and desensitize the torturer. And on that level it seems to work just fine. It's horrible even to contemplate the miseries that were visited on McCain, but they did not happen in a vacuum. Actually, they did happen in an utter moral vacuum, one in which a great many Americans took several decades to finally reach closure, and forgive the Vietnamese for what we did to them. And a remaining few never will let it go, even though the Vietnamese moved on a long time ago. Insisting on calling them wogs, when there's no practical or even political reason to do so, just keeps the ball rolling.