It goes against the postmodernist ethos to allow those we don't agree with to speak. It's a weird concept because a lot of people don't have anything worth a damn to say. However, when you police the discussions people are allowed to have along the narrow lines that surround your comfort zone, you limit your intake of information, and as a result, limit yourself.
Sure, it's easy to say that the KKK and neo-nazis shouldn't have a voice because they use their voices to spread hate and xenophobia to those individuals feeble-minded enough to listen. Although the latter is true, when we do that, we actually set ourselves back. Bear with me on this.
The thing that makes this country unlike many is our ability to say whatever we want. Literally, anything. If you think about it, it's weird to limit people's ability to say what's on their mind. You not only silence dissent, but you restrict people's ability to process what they're thinking and feeling. You obstruct people's expression. It's a scary concept.
There are a lot of places with actual dictators that are a hell of a lot worse than Trump. Places where speaking ill of the regime is a punishable offense. This isn't a call to appreciate how lucky we are, it's an insight into how unlucky the rest of the world is. As well as to recognize the importance of being able to say what's on your mind. They lose a great deal of personal freedom when their thoughts have to be censored. So, when we stifle someone, no matter what they're saying, we become part of a problem that has plagued people living under authoritarian rule since the beginning of time.
We all want to be on the righteous side, fighting injustice wherever we see it to let these buffoons preach a narrative that is completely backward at its core. When we silence people we set a dangerous trend. Things like this tend to snowball. When we allow the limitation of free speech in any way, we create an in for people with ulterior motives to quell any dissent. It opens a door that will become increasingly hard to close. That's not to say that we should listen to every idea from every mouth. While listening to other people who think differently than you is central to broadening your worldview, there are certain repugnant fringe groups that have nothing important or relevant to say.
So, what should we do? How do we address the slew of sickos out there who spread a message of hate? We don't. We ignore them. The answer here is not to try to stifle them, it's to do your best to not listen. When you've got a crying child, there are two things you can do:
A) You can give the child the attention it wants and try to get it to stop crying that way, showing it that if it wants attention all it has to do is cause a scene.
B) You can ignore it, and show them that crying and yelling is not going to work.
When you do the former, you reward the negative behavior and give them the power. The latter shows them that they don't get to control you through those means. As a result, they become a lot more docile over time.
We complain about this seemingly sudden emergence of new racially motivated hate groups, but all it is is the media giving them the platform to speak. This has shown people that being a loud, racist bigot is a great way to be heard and seen. They've always been there, but now they feel they have a group of like-minded racists in the limelight to join.
This is a case of out of sight out of mind. We can let them talk all they want, but at the end of the day, their outdated ideas mean about as much as flat earth theorists. We don't need to take away their right to speak because that's a concept that could blow up in our face. We just need to ignore them.