One could make a case that in the White House, the track record of the fighting men has been more consistently successful than that of the former generals and other senior officers. Perhaps that's because the fighting men learned how things really worked from the bottom up and saw firsthand the realities of human nature.
In the end, McCain's POW buddies present a strong case. Their praise for McCain is not the only factor that voters may have in mind, given today's economic distress and other pressing domestic problems. But their main point is a simple one, that character counts.