Tha "adversity" that McCain faced in Vietnam was a bit more personal and in-your-face than what Lincoln faced. Fault him for his politics and policies since then if you must, but to fault him for not being Superman while in some VC toilet is, frankly, ridiculous.
I do not fault him for his experience as a POW. Of course not. But I do not support this man as he is less conservative and less Republican than many Democrats starting with Zell Miller.
Between McCain and a Democrat running in 2008 I'd just as soon have the Democrat who will be a Democrat and not pretend to be a Republican as opposed to McCain who will really be a Democrat while pretending to be a Republican.