Craig - free speech is a right we have that the government can't take from us, but that literally has nothing to do with everything else that you just typed.
This board is not a governmental body, but a purely private affair with user rules that we agree to when we sign up, and a (likely small) number of moderators that manage the board to thwart spammers, maintain data security, and enforce the rules we agreed to.
Now I have no idea about what might have happened with the post in question, and I didn't get a chance to see it myself, but given behavior observed to date I'd would imagine we could just as easily speculate that Rick made some statement(s) that were out of bounds in the thread (and if that were the case I'd wager more likely than not it would not necessarily be an intentional act, but a result of constantly taking a one sided view and assuming any other perspective to be of malicious intent directed against his windmill/goal), or in direct messages with a moderator, as we could imagine that SCCA black helicopters surreptitiously shut it down for "political" reasons.
Since we have no reason to believe either theory, I'll go ahead and not jump to conclusions unless we learn some information to go from.