I certainly won’t call it a surprise endorsement; Cindy McCain and John McCain were friends with Joe Biden for several decades, afterall. John McCain himself is also very rare breed of Republicans. These people don’t let their differing views and beliefs stop them from being openminded and hating everyone who don’t share their worldview. John McCain, in case you missed it, defended Obama Care, his vote being the one vote that saved hundreds of thousands of Americans (Note that McCain was also Obama’s opponent in 2008, who was initially cynical of Obamacare.) I should also add that even Meghan McCain (who isn’t bright most of times) defended her mom’s endorsement. She herself has also hinted at voting for Biden, though she has yet to officially endorse him.