If John McCain had betrayed his country, NONE of the his fellow POW's would even give him the time of day. It'd be like in 2004 with John F'n Kerry (who served in Vietnam), with ALL his fellow officers coming out against him, while a few of the enlisted guys under him supported him.
Instead, his fellow POWs all support him and his candidacy. Bud Day's endorsement is good enough for me.
I read a number of studies on POWs held by the North Korean and Japanese, doing research a while back. An interesting thing about it is that those POWs, especially ones that were badly mistreated, were very, very lenient about judging others who held strong at first but eventually broke and collaborated. On one hand, you'd think that it would make you more biased against them, but the consensus largely seemed to be, "You don't know what it's like, they only did what they had to do to survive."
Most Americans can't imagine what brutal captivity would be like.
In that regard, Obama, and his surrogates, who have suffered nothing for this country, are in no position to judge anything. McCain never said worse about his country under torture than Obama said of his own whimsy in Bill Ayer's living room.