Telling your climate change denying uncle he's an idiot won't change his mind, but it will ruin thanksgiving. That's why it's important to consider if your emotions are leading you to do something counterproductive.
Why is there selected group of people and opinions who can run their mouths and everyone else must shut up else they destroyed the event?
This is nice example how something completely different: social hierarchy where it is super importsnt to keep illusion that some people are right.
Usually it does change his mind if he respects you enough. It wont work on a stranger but it is very effective on long term friends.