My husband and I participated in a political movement. My husband believes that the movement's actions were ineffective and even counterproductive, that they failed to live up to their ideals, that many of them were opportunists or traitors secretly working for the opponents. He feels that the movement has bullied him, treated him unfairly and failed to support his initiatives, so all the effort he spent on it was wasted. He feels betrayed.
I think that most of my husband's criticisms of the movement are valid, and his feelings are understandable. The problem is that he finds some person on the internet who belongs to the movement - not necessarily someone he knows personally. He starts arguing with them, and shows the resulting conversation to me, saying "Look what an asshole they are!" When I look at it, I see that the other person politely made some innocuous comment, and my husband took offence to it and responded with extreme rudeness and vitriol. Then the person responded in kind or blocked him.
I try to tell him that the other person wasn't the asshole in the conversation. My husband starts explaining how bad the movement is, how it has wronged him, and how therefore people in it do not deserve politeness or respect. I am trying to get him to see that the person he is talking to is not the same person as all those other people who hurt him; that sometimes people hold stupid beliefs because they made a mistake and just need that mistake kindly pointed out to them. I think most people in the movement are well-intentioned people who confront significant danger to try and do the right thing. The mistakes they make are mostly caused by stupidity and not ill intent. I tell my husband that I agree with his criticisms of the movement and understand his feelings, but I don't think they justify viciously attacking people who haven't wronged him and who were talking to him politely. He thinks my defense of them means that I don't understand him and that I am loyal to the movement over him. He feels very hurt by this.
I suggested that he stops showing his internet conversations to me, as that just leads to another argument that gets us nowhere. He feels that was rude of me and that I am trying to shut him up.
Ideally, I'd like him to stop attacking people, some of whom are my friends. Failing that, I want to at least stop getting into arguments about it. However, I am not willing to pretend that his behavior is justified. How can I achieve my goal without making my husband feel misunderstood and unsupported?