I have heard that McCain turned down early release from Vietnam when it became known he was an admiral’s son. If true, he is most certainly a hero, but I don’t know if it’s true.
That is the Left's talking point, he made a choice to stay behind. Now flip the coin, let's see what would happened had he come back. Would the Nave have welcomed him? Would his family? What about the families of other POW's? It would have been, politically, tremendously divisive. And say goodbye to any thoughts of a career. So in reality he had no choice, but the Left seized upon this as proof of his character. That's all they had.