Republican Senator John McCain's voice and opinion regarding Guantanamo Bay is reasonable and sensible. His experience during the Vietnam war as well as his time as a Senator makes him an authoritative person when it comes to this controversial issue. His personal and professional life experience makes him the person worth listening to.
John McCain is a veteran and is probably as qualified as anyone to make a decision on Guantanamo Bay. I believe his combat experience makes him more thoughtful than a lot of Republicans when it comes to military matters that have long reaching consequences. Whether I like or agree with his decision is another question, but he is no doubt qualified to make one.
I'm no fan of John McCain. I was in his earlier, more "maverick" days as a senator that would reach across the aisle, but not so much now. Anyway, yes, I do think he is qualified to do so based on his history and the fact that he was once a POW.
As a democrat I actually like John McCain quite a bit. I don't think he's president material and he picked a terrible running mate, but he does have a lot of political experience and I would trust his suggestions regarding Guantanamo Bay. I think John McCain has received a lot of bad press for bad reasons. He's qualified to make suggestions on this matter.