Perhaps the oddest thing about the American legal system is the separate state, federal, and administrative courts. The law in federal court can be completely different than the law in the state courthouse next door. And on that same note, an antitrust lawsuit that would be a guaranteed failure in federal court might have a fighting chance in a Florida state court.
Major League Baseball's antitrust exemption is common knowledge by now. In 1922, the Supreme Court declared baseball a game, not a business, and therefore exempt from antitrust provisions. In 1953, SCOTUS compounded the error by upholding their prior ruling, citing Congress' inaction to remedy the problem as justification for continuing preferential treatment. Nearly 20 years later, Justice Blackmun wrote an odd ode to baseball in another upholding of the exemption, this time justified by stare decisis.