Conventional wisdom says it’s the retirees.
Even where I’m at in Cochise County the retirees that don’t vote Democrat seem entirely devoted to McCain regardless of any facts presented to them. There are exceptions of course but the maybe three dozen I have talked with are mostly supporters and can’t get past “he doesn’t take earmarks!” and “viet nam war hero!!!”.
That’s all anecdotal and purely my own observations so take it for what it’s worth.
Maybe SandRat or others have different experiences.