I think 100% people shouldn't make racist/sexist/homophobic/etc comments. If I say something that offends someone I hope they'll politely show me how I hurt them so I can try and avoid it. I get too passionate sometimes when I discuss issues (I apologize for that), and I grew up in the 80's and some of our vocabulary is not unknowingly offensive. I make mistakes sometimes. If those hurt people I'm truly sorry and want to do better.
But not everyone's like that, and we all have to live together. You can only change yourself. Changing other people requires some kind of violence, and using violence to cut out hate just makes things worse. For everything there is an equal and opposite reaction. Trump's whole persona is an awful personification of this.
We've come a million miles over the last 2-3 decades in respecting people who are different from ourselves. I think the stragglers will be won over, but it will be with love (maybe firm love), not with punishments and fear.