editorializer

/ˌɛdɪˈtɔriəˌlaɪzər/
noun
  1. A person who expresses strong opinions or commentary, especially in a way that resembles an editorial.
    • He is known as a sharp editorializer who doesn't shy away from controversy.
    • The newspaper's chief editorializer wrote a passionate piece about climate change.
    • As an editorializer for the blog, she often shares her views on local politics.