The decline in strength, density and influence of the labor movement must be a concern for all of us—even if we are not union members. It has led to stagnating and/or declining wages and benefits for private-sector workers, undermining the entire community. In a Hobbesian world of labor markets, no single sector or group can remain an island of good wages and working standards in a sea of declining standards and conditions.
In addition to the economic impact, the decline in unions also has had a detrimental impact on our democracy. The fact that the union movement builds democratic communities is crucial—but little recognized. By bringing together workers who have few rights, who are isolated as individuals and often compete against each other, unions forge a community in the workplace. They help workers understand they have rights, and they provide a vehicle for exercising those rights. They provide a powerful check to the almost total power of management in the workplace. And they fight for the right of workers to participate in decision making in the workplace.
http://www.aflcio.org/mediacenter/speakout/elaine_bernard.cfmArticle.