We went a bit on the same crisis with my father which is a lot into politics and discuss at length about how the rich are conspiring to maintain their power, and how all politicians are corrupt with proofs he would have either completely made up or read somewhere that's nowhere near reliable or objective. And I, well, would define myself as a moderate liberal. I was pretty angry some of his views got adopted by my brother and sister and there was a time where I would often confront him about how things he said were off. This felt like "the right" thing to do, and at the same time it was dragging my energy terribly and made me want to distance him more and more.
There was a day where I came to visit him and he went on a rant about the rich again, and since I had no energy to fight that, I did absolutely nothing but wait for him to be done. Eventually, he ended on a personal statement about how he felt about that, that I found interesting.
This day I realized that proving anything is kind of vain, we are close family that should be celebrating moments of our life together, share our feelings, share our experiences, but not necessarily share every opinion. So I decided myself I would either avoid the subject completely if I don't have the energy to participate, or I would ground it back to how someone personally feels about that.
You say that avoiding the subject of politics left you with uninteresting conversations. I would think that if you feel strongly about a political subject, it would not be irrelevant to talk about it. But instead of trying to prove a point, especially when it gets passionate, you could instead simply question and listen to them. Try to understand how they feel about it, and respond with your own feelings, or to the part that affects you.
As an example, I remember a debate about how careless people were acting about COVID when it was still early epidemic. Instead of debating the specific statistics of contamination chances I asked instead "Do you personally know someone vulnerable?" and that gave a very clear view why people took alignment toward one side or another.
Over the time and when the context allow for the debate to be interesting and peaceful, you would want to debate a particular subject. Note that I would in first intention try to avoid debating, but if you feel like you reached a point where both opinions would be mutually respected, you could give it a try to debating again. Doing so, you can take extra care to express rebuttal in a more compassionate way. Taking examples there, you could use the following wordings:
- Can you explain why you think/say that?
- I can see why you would say [premise] but I'm not sure why you conclude [conclusion].
- Let me see if I correctly understand. [Repeat the reasoning, asking if it's correctly understood] I can see where you're coming from but [add contradictory evidence].
Additionally, it is very obvious to me that using judgement such as "You are wrong" could be damaging to your relationship. Even if you think you have more evidence on your side, that is still just your opinion.
In short, and contrary to what your professional experience might be, I'd suggest to focus on compassion and listening first, and getting facts corrected after that.