The on-going political rancor, and more recently the confrontations over Confederate monuments, has really brought home to me the need for sympathy and validation when trying to persuade people to change their minds. If you are unwilling or unable to acknowledge their current position as a valid response to their past experiences you will never gain their trust sufficient to allow them to change their minds. There's an element of vulnerability in conceding an argument, and I cannot be vulnerable with people I don't trust. You must be trying to convince me to think differently because you have my interest at heart, not your own.
For example, many of Donald Trump's fiercest critics cannot allow his supporters to be anything other than evil or stupid (or both). The critics who do manage to get past this are usually stuck on the next obstacle, which is to condescendingly say his supporters are misguided. This will never change anyone's mind. People react defensively when called evil or stupid, or when patronized. But where is the Trump critic willing to say to a Trump supporter, "Your support of Trump is a logical position for someone who has seen and experienced what you have, and had I experienced your same life experiences, I would probably be a Trump supporter myself"? That would be the beginning of a true dialog interested in bettering the country instead of what we have now, which is just an argument between parties interested in being right.