The first thing we need to do is be sure we do not join it.
Jesus talked about removing the plank from our eye before trying to remove the speck in someone else’s eye. The deeper understanding of this proverb is that the plank and the speck are made from the same substance. In modern terms we would say that the attribute that bothers us the most in someone else is most likely the same attribute that is present, but denied, in us. If we are bothered by the behaviors of others, then we are probably doing the same thing. It is much too easy for us to hate the haters. Which means we have joined their culture.
After we determine that our own character will not become one that exhibits hate, then we can enter constructive dialog with others and keep our character intact. We need to determine that we will stay loving.
We will seek to understand without assuming evil intent.
We will state our points of view clearly and kindly.
We will show our genuine, loving humanity including our vulnerability.
We will present the alternative to hate and fear.
Most people will be drawn eventually to a more positive loving relationship if one is presented to them. If both sides of a debate descend into fear and hate, then neither has presented an attractive alternative. For people to turn from something, they need to have something to turn to. Present them, in your words and your actions, a picture of a more attractive alternative.
When you demonstrate a way to a better future you will be a witness. The Greek word for witness is martyr. It is not without reason that we associate death with martyrs. Hatred does not give up easily. We should not be so naïve as to think that our loving witness will be instant magic that changes everything to rainbows and lollipops. It will take consistent love even in the face of resistance and danger.