All "rights of free speech" have to be balanced by other peoples' rights to go about their business without being insulted or denigrated
The "slippery slope" idea is far too often uses to have the unacceptable accepted
We have a troll wandering around here at present putting forward the same argument
If people demand the right to behave inappropriately, they must to accept the right of others to ask them to stop or at least, make their feelings obvious - I've seen that happen more than once and enjoyed it

I was both alarmed and amused by the story of Eric Bogle singing his bitterly anti-racist, 'I Hate Wogs' when a member of the audience climbed onto the stage and punched him - critical acclaim in the extreme
Jim