Sentence:  He has the annoying habit of <WSD>proselytizing</WSD> [his political views] at parties. 
Meaning of the word marked with <WSD> tags:  To advertise a non-religious belief, way of living, cause, point of view, (scientific) hypothesis, social or other position, political party, or other organization; to convince someone to join such a cause or organization or support such a position; to recruit someone.