I can't say I've ever seen a post that I disagreed with enough to consider blocking the person behind it. However, if a person posts content that consistently makes you uncomfortable and may lead you into conflict with them I think it's ok to block them. It's not worth it to simply uphold their right to be heard. However, if you simply disagree with a person's views (assuming they are well though out and not terribly militant) I think it's healthy to not block them and see their side of the issue.
In contrast, I have seen posts that just made my blood boil. I have set one person to ignore and came close to ignoring another. Note that I chose to ignore instead of mute. It puts a slash through the person's name, a calm equivalent of a red flag. This reminds me that said person is prone to tactics that anger me, so I stop myself well before I reply. Then again this same person has contributed nicely to (non-political) topics. Thus I don't want to mute said person, unable to get the good with the bad. One time that person and I agreed on a topic in ways that dovetailed nicely with the conversation. Thus I was glad to have the mark and the content.