It's almost certainly not possible for you to have a discussion about feminism with such a person.

I haven't read your blog, but perhaps you should reconsider the kind of community of readers you're trying to build there. If you tend to attract antifeminist posters, and you don't also attract profeminist ones who help you argue your position in the comments, that sounds like a totally unproductive community and you might want to take explicit steps to remodel it, e.g. by changing your posts, controlling the allowed posters, or starting from scratch if you have to.