People aren't mentioning this, but this has already happened.
I'm not white, just to be clear, however back sometime last year I knew infrastructure-level censorship was coming when DNS services, GoDaddy in particular, started censoring sites. The canary in the coalmine was the Daily Stormer.
It's one thing to want them to be quiet. It's another thing to set the precedent of infrastructure forcing them to be quiet. As you said, it sets a precedent.
EDIT: DNS censorship has indeed been mentioned in this thread.