I really can't get over the fact that THIS is what people are calling "over-the-line." Trump has been spouting crazy shit since his announcement and has taken almost no heat, at least not from the right. Now he finally seems to need some damage control, and it's not because he wrote off an entire demographic of around 54 million people. It's because he made one petty comment about a man who could probably defend himself just fine on his own.
You don't degrade prisoners of war when running for office. It's sort of a no-brainer. The fact that he has zero chance of getting any of the hispanic vote is also problematic, to say the least. You are right about McCain, he can defend himself and he took the high road. Why disparage Trump? He's digging his own grave right now, McCain knows better than to take the shovel.