I would fight to defend someone's opinion that I disagree with completely.

As a defender of their rights, even if the opinions were offensive to me   I care that they can express themselves as long as nobody is getting hurt. There were hate papers left all around an area in the town I used to live.  I talked to the police and was told that democracy in order for it to work must allow for all kinds of speech, though littering is illegal.  Take their freedom away and then you have no right to your own freedom.  At least my intolerance or dislike could create widespead tape over people's mouths.  Not a fertile ground for new ideas or progress or learning.