POW or traitor? Or just insane?
There's a third possibility - as I've suggested in the past, if we assume McCain's story (POW who was abused) to be true, then it is possible that he went mad as a result of his treatment, was mad upon arrival to the USA, and remains mad today.
One can look at his behavior, including his rages, which points to this. Perhaps - who knows? - sitting in his Vietnamese cell, McCain "broke" mentally, and blamed America - specifically traditional White America - for his imprisonment and torture.
Perhaps, in his demented mind, he is "getting back" at traditional White America by championing open borders and the race replacement of those who "abandoned him in Vietnam."