Two recommended communication techniques are to isolate trolls and to stick to your frame and values. These ideas are often in tension:
For example when neo-Nazis and white nationalists grab torches and march through our streets, we can isolate them and their supporters relatively easily, or talk about institutionalized and unconscious bias — where we have a lot of work to do before there is near-universal agreement.
Isolating trolls means finding a way to remind the vast majority of Americans that we are all against people with swastikas, together. Perhaps reinforcing the idea a bit ahead of the current reality, proclaiming the world we want optimistically. It is a reasonable, achievable goal that any politician who associates with white nationalists, swastikas and domestic terrorists can be politically utterly ruined.
Speaking from your frame means calling out the existing racism and privilege, such as failures of most police departments to deal with institutionalized racism. Racism is a deeply entrenched disease in the US; there is a politically powerful demographic that doesn’t see it yet, a giant education campaign ahead — we can't use isolation techniques on that large a population, we have to convince people to change their minds.
On swastikas, we are not divided into two, and have to prevent that situation from getting worse. On institutionalized racism there is not a unified super-majority in agreement.
When discussing these issues, especially online, it’s important to decide whether you are speaking your heart, or isolating a troll — and to do both, but not do both at the same time. When Trump associates with people who use the Nazi “blood and soil” chant, attack him from the center, attack him as an American — isolate him, for that moment don’t represent liberals or the left ... which will press many conservatives to feel aligned with him. At other times, when it is time to really move forward, ignore Trump (don’t say “No” to his position), and proudly state your most idealistic vision.
In social media, it is often a two-step process. Think of it as walking through a door: the first step is to open the door, countering outrageous politicians in a way that supermajorities will feel united with you. Then walk through it, being respectful while challenging, and including ourselves in the group that needs to work on changing.