Progressives: In the New York Times report on Trump's taxes: what in it would disturb a possible Trump voter (not necessarily a core Trump voter) the most?
Listen to the other person, paraphrase their points, see if you have heard them well, and ensure they feel heard. There are various slightly different approaches to active listening; it is part of most effective communication techniques. One to one, make sure you don't just listen, but that the other person knows you listened. With social media posts "listening" isn't always possible, but you can still get close: make sure people realize you've read or heard their points, before diving in to your own.