Concerning the legality of Sports ociation fines.?

I don't know all the facts of individual cases, and feel they may well further cloud the waters. However, it seems to me that a private club is illegally posing as Government, the Judicial Branch, by imposing monetary fines on players. This has frequently resulted from actions by the players which violated club guidelines, but did not break actual laws at the time. It seems to me that a private club is limited by law to various forms of withholding access to the club, as its sole remedies for disagreements with the players over style. Attorney of note John Parkhurst once said to me, "Don't get bogged down with platitudes of what Ought To Be. In Court, it's a question of what the precedents are which constitutes What Is." That day we were short on precedents! So what I ask, is whether the precedents are legal or cultural allowing private clubs to rob people? Or are there legal precedents where private clubs were blocked from doing so? Or upheld in doing so? Just currious. Regards, larry