Most of boards are privately owned. They can make any rules they damn please, and if you don't like them you can find another. Sadly, USMB has become a bit of a landing strip for those who spout such ignorance.
And the same to you, of course: why are you here if you hate it so much? I'm always surprised by people who want everyone else to go away while they stay and swan around. If what you are looking for is a leftwing PC-controlled Orwellian-nightmare forum, why not go to one of those since you are suggesting you know where they are. Instead, you want to shut everyone else up so they only say what you let them say. This is how the Left works, and is perhaps the single worst thing about the Left.
I don't like a lot of violence talk or personal insults, but I can remember when the Ignore function was invented in forum software (and spread like an Australian bushfire), which basically solved all the problems with people too awful to be around. The race is on: which of us puts the other on Ignore first?
Then we'll never know what each other really thinks. That's sure to solve everything.