There is a long-standing bias in Catholic social teaching toward unions, and this dates from the long history of labor struggles for fair wages and safe working conditions. There is a romance associated with this history, and it is bound up with strong moral concerns. And it is not just historical. The Catholic Church played a heroic role in the fall of Communism in Poland through its influence on labor unions that were striking against oppression, which is to say state coercion.
Pope John Paul II, who knew something about the social role of labor unions, also warned about their drift into politics. In his encyclical Laborem Exercens, he wrote: "Unions do not have the character of political parties struggling for power; they should not be subjected to the decision of political parties or have too close links with them."