actually, that is quite wrong.
you are right about the right to hire but blacklisting in an industry is a good, good way to get federal eyes and regulation into an industry. further, it can easily, easily be called civil or business conspiracy and a good way for businesses to find themselves with a multi-million dollar bill. the only time a business will even think of following an industry blacklist should it exist is if they're exceptional or if the labeled individual actually did something repugnant and the company can easily point to something objective that came to the same conclusion, like an actual criminal trial and sometimes, though rarely, a lawsuit.