Individual labor unions, like any organized constituency, sometimes have interests that conflict with the greater public’s. Police unions have an interest in protecting their officers from legal liability; the public, in ensuring that those who are supposed to “serve and protect” us have ample incentive not to shoot us dead. Coal miners’ unions have an interest in perpetuating their industry; the public, in perpetuating climatic conditions conducive to human life.
But these conflicts do not render organized labor — as a whole — a “special interest group” like any other. While certain unions may be an obstacle to the greater good on discrete issues, they are collectively a uniquely effective vehicle for realizing that good on the issues that matter most to working people.