One of the hardest things to do is understand someone with an opposing point of view.
Often when we think we understand we actually don't and from this false understanding comes judgement and criticism.
The trick is not to take it personally and ask questions to get more information.
For instance. If someone writes something that you think is offensive or racist, instead of getting angry. Ask them why they feel the way they do.
Right or wrong people feel the way they do because of their personal experiences from their past. Some of it is also their up bringing.
The point is people are people and by nature are unique. Regardless of their politics or beliefs they deserve to be heard.
Also... You'd be surprised how far you can get by being respectful to someone.