I like to stand up on it and yell out my views. Sometimes I let my friends use it that way, too.
Some guy comes along and would like to use my soapbox to yell out his views. But I don't like him and I don't agree with his views.
Would you like the government to come force me at gunpoint to let him use my soapbox?
What you're arguing, basically, is that once my soapbox gets popular enough that lots of people want to use it, you do want the government to force me, at gunpoint, to let them use it even when I find their views repugnant.
Or, basically, what this person said, and they said it better and in fewer words:
https://twitter.com/lessdismalsci/status/1076488300188307456