I'm looking for a phrase or (ideally) a single word to describe someone who dismisses any opposing opinion as being wrong and a result of being unable to think correctly. Ideally it would also imply that the right opinion is obvious and anyone who doesn't hold it does so due to a lack of intelligence or deliberately disingenuous thinking.
I've looked at Word for someone that always has to be rightWord for someone that always has to be right and Word for dismissing someone's opinions as racist, liberal, etc, instead of debating backWord for dismissing someone's opinions as racist, liberal, etc, instead of debating back but I feel like they don't capture the implication of stupidity/deliberately incorrect thinking.
The closest I can come up with is disingenuous however this doesn't really fit. The word should refer to a person who dismisses opposing opinions as disingenuous (regardless of whether his own opinion is correct or not).
