I don't know how to grade myself on clarity of communication, but I'll share some things I think have helped.
Avoid long sentences. Many people don't read well, and even those that do will get lost in a long block of text.
Read back what you wrote out loud.
Do not neglect the emotional front. Conversations and convincing are about emotions more than facts. Acknowledge their position. Make them feel heard.
Read more. Read a variety of things. Op-eds in newspapers. Books of various genres. Old stuff. New stuff. Feed your brain more than word junk food.
Ask questions. Sincere questions. Don't try to trick them. People are usually happy to talk about themselves and their beliefs. Use this to find common ground and shared experience.
You can't just kill them. You need to deal with the forces that enabled them. But getting rid of them would be a good start.