The book Nonviolent Communication might be a good starting answer to the question "How to discuss politics (race/gender/...) rationally". I can also recommend Leadership and Self-Deception. If you really want something that's been posted to LW, may I submit a couple of my posts? And Scott Alexander has good social justice stuff on his blogs, e.g. this (though he might make too many object-level statements for his to be good material for canonicalization).