Before your eyes is the inaugural edition of Christian Democracy. Like the Israelites who first saw the manna in the desert, you might be led to inquire: “What is it?” Christian democracy is probably best defined as activity directed toward the implementation of Catholic social doctrine.  Considered as a movement, it goes back to the days of Pope Leo XIII’s 1891 encyclical Rerum Novarum , which Pope John XXIII seventy years later called “a compendium of Catholic social and economic teaching.” 
As the nineteenth century progressed it was becoming obvious that humanity in the Western world was separating into two classes: the small number of wealthy capitalists, and the great mass of working people who were confronted with wretched poverty.  Factories were thriving, but wages were insufficient to subsist on.  There were two main ideological responses to this situation.
The capitalists, who found themselves benefiting from the prevailing economic system, were pleased to view the conditions as the inevitable outcome of economic laws. These laws must be respected, it was said, and any governmental interference with market forces would only be damaging to the fabric of the economy. The human casualties of capitalism, it was held, could best be handled with private charity.
The other response was socialism. Starting with the obvious observation that the prevailing economic system had no convincing argument for the vast majority of people, the socialists maintained that the major defect in the system was the private ownership of the means of production. The few who owned the factories were in a position to determine the price of labor, and would always determine it to their advantage. The downward pressure on wages was a permanent feature of the economic system. For the socialists, then, the answer was to wrest ownership of the means of production from private hands, and vest that ownership in the public, that is, in the government.
There were Catholics, both clergy and laypeople, who felt strongly that their religion required from them some response to the plight of the working masses. But the circumstances were unprecedented, and it was not easy to know what would constitute a Catholic response. There was the Catholic tradition of charity, of course, but charitable institutions by themselves seemed unequal to the task of righting the human calamity that had been brought about so systemically and on such a massive scale.
It was in these circumstances that Pope Leo XIII was approached by some familiar with “the social question,” as well as by employers and workers, to address what the proper application of the Gospel was to these new conditions. Rerum Novarum was his response.
The Latin title of the encyclical is usually translated “New Things,” and, indeed, it was an economic situation completely new to the world that Leo XIII was addressing. It was a situation characterized by conflict born of the vast number of new industrial activities and scientific discoveries, of changed relations in the workplace, and, perhaps most of all, “in the enormous fortunes of some few individuals, and the utter poverty of the masses….” The purpose of the encyclical was to address the condition of the working classes, the poverty to which they had been reduced, and the appropriate remedy in light of Catholic doctrine.
There was no doubt in the mind of Leo XIII that such a remedy was needed. Something had to be done for the workers who had “been surrendered, isolated and helpless, to the hardheartedness of employers and the greed of unchecked competition.” Exacerbating the problem was the practice of usury, and the concentration in the hands of very few the means to hire labor and conduct trade. The result was that a small number of the very rich had “been able to lay upon the teeming masses of the laboring poor a yoke little better than that of slavery itself.”
Still, Leo XIII felt obligated to reject the solution offered by the socialists. He observed that one works for wages not only for his subsistence, but also for the acquisition of property. Property is precisely the means by which workers could better their situation. But the socialists wanted to deprive workers, along with everyone else, of the right to acquire property. While the capitalists deprived the workers of property through exploitation, the socialists would have accomplished this through government fiat.
The Pope’s response was to articulate a labor theory of property. Property initially arises, he said, through the labor that a person expends on nature, using as an example the cultivation of a field that was previously in a wild state. Strikingly, and in contradistinction to prevailing theories in his day (and ours), he set forth as a law of nature that property is derived from labor. “Is it just that the fruit of a man's own sweat and labor should be possessed and enjoyed by any one else?” he asked. His response was definitively in the negative: “As effects follow their cause, so is it just and right that the results of labor should belong to those who have bestowed their labor.”
Thus, the socialists would have deprived labor of its very motive. But the capitalist answer to the prevailing social conditions was equally inadequate. Just as property derives from labor, so the motive of labor is property. This does not mean that one cannot legitimately hire out his labor, but it does follow that when a person hires out his labor for remuneration “he does so for the purpose of receiving in return what is necessary for the satisfaction of his needs….” Thus, if a worker receives less than that, labor’s very purpose is defeated. What’s more, if a worker’s remuneration is less than what is necessary for him, he has suffered a violation of his natural rights, since “each one has a natural right to procure what is required in order to live, and the poor can procure that in no other way than by what they can earn through their work.”
Leo XIII described the capitalist position this way: “Wages, as we are told, are regulated by free consent, and therefore the employer, when he pays what was agreed upon, has done his part and seemingly is not called upon to do anything beyond. The only way, it is said, in which injustice might occur would be if the master refused to pay the whole of the wages, or if the workman should not complete the work undertaken; in such cases the public authority should intervene, to see that each obtains his due, but not under any other circumstances.”
This view the Pope rejected. Contracts are fine, he said, but there is a more foundational consideration. It is a requirement of justice that wages not “be insufficient to support a frugal and well-behaved wage-earner.” If a worker finds himself compelled to accept pay less than that because of the desperation of his circumstances, then he has become “the victim of force and injustice.” The fact that inadequate pay is a contract term does not elevate it to the status of fairness. The same holds for other conditions of employment, such as labor hours and sanitation in the workplace.
The Pope also disagreed with the limited role for government proposed by the partisans of capitalism. He did not concur with the notion of the state being reduced to the function of an umpire, but envisioned a positive and proactive role for the government, particularly with respect to working people and the poor. He observed that “it lies in the power of a ruler to benefit every class in the State, and amongst the rest to promote to the utmost the interests of the poor; and this in virtue of his office, and without being open to suspicion of undue interference - since it is the province of the commonwealth to serve the common good.”
Leo XIII was far from sanctioning any idea that the casualties of the economy should be left to the efforts of private charity alone. On the contrary, he was of the view that the government should do what it could to reduce the need for such charity. As he put it, “the more that is done for the benefit of the working classes by the general laws of the country, the less need will there be to seek for special means to relieve them.”
For Leo XIII this was not a matter of kindness but of justice. For him, working people are entitled to this consideration by the State. His reasoning was this:
“We have insisted, it is true, that, since the end of society is to make men better, the chief good that society can possess is virtue. Nevertheless, it is the business of a well-constituted body politic to see to the provision of those material and external helps ‘the use of which is necessary to virtuous action.’ Now, for the provision of such commodities, the labor of the working class - the exercise of their skill, and the employment of their strength, in the cultivation of the land, and in the workshops of trade - is especially responsible and quite indispensable. Indeed, their co-operation is in this respect so important that it may be truly said that it is only by the labor of working men that States grow rich. Justice, therefore, demands that the interests of the working classes should be carefully watched over by the administration, so that they who contribute so largely to the advantage of the community may themselves share in the benefits which they create-that being housed, clothed, and bodily fit, they may find their life less hard and more endurable. It follows that whatever shall appear to prove conducive to the well-being of those who work should obtain favorable consideration. There is no fear that solicitude of this kind will be harmful to any interest; on the contrary, it will be to the advantage of all, for it cannot but be good for the commonwealth to shield from misery those on whom it so largely depends for the things that it needs.”
Working people contribute to the common good. Indeed, without working people it would be impossible for a society to obtain any wealth at all. It would be an injustice, therefore, for their interests to be disregarded by the State. Moreover, since the reduction of working people to poverty and misery could only hamper their abilities in the production of society’s wealth, it follows that shielding them from such eventualities can only enhance the well-being of society as a whole.
Still, Leo XIII was no statist. While he disagreed with the capitalists as to the necessity and propriety of government intervention in labor matters, he believed that associations of workers, or of workers and employers, would be better able to deal with the crisis he was addressing than would an overly heavy hand from government. The most important of these, for Leo XIII, were labor unions.
To be sure, the Pope hoped for more from unions than what ultimately developed. He envisioned unions as a support for the spiritual needs of workers, as well as their material betterment. But he saw them as a critical component of the effort to enhance the condition of working people. What’s more, he viewed their formation as an expression of workers’ natural rights.
Since Rerum Novarum the Catholic Church has developed her teachings regarding the rights of workers and their unions. Unions are not viewed by the Church as merely permissible, but as “a positive influence for social order and solidarity,”  and “therefore an indispensable element of social life.” The Church also recognizes the right of workers to strike when circumstances become serious enough.  What the Church has never said is that this right is restricted to certain workers. On the contrary, she recognizes that while the struggles that gave birth to unions especially involved industrial workers, workers in general were involved as well.
There are two contemporary notions circulating that should be addressed in light of the foregoing. The first is that social and economic conditions have changed to the extent that historical Church teaching regarding labor unions and the rights of workers should be viewed as a creature of a particular historical context no longer obtaining. The second is that Church teaching regarding labor unions, even if it possesses continuing validity, has no application to public sector employees.
It is Catholics who have been thus opining, unsurprisingly, since those who are not Catholic will see little need to consider whether their social and political opinions are in line with Church teaching. On the other hand, it should be recognized that there are others who will take an interest in how these issues are resolved among practicing Catholics, and should not be naively expected to sit completely on the sidelines as such controversies develop. What Catholics believe regarding political and social issues will impact how they vote, and it is in the interest of political parties and factions to present their platforms as consistent with Catholic social doctrine.
The response to the first notion is that the only relevant historical context is that where capitalism is the pervading economic model. Unions developed because of the downward pressure on wages that is characteristic of capitalism. Lower business costs mean greater profits, and, because of the continuing surplus of available labor, the employer is generally in the superior bargaining position. Unions provide a necessary counterweight to this tendency, as is evidenced by the better wages enjoyed by union workers over those who are non-union.  The only way that unions can be eliminated with the same benefits for working people obtaining would be with more direct government intervention, which, presumably, the advocates for the so-called free enterprise system would not favor.
As for the applicability of Catholic teaching regarding unions to public sector employees, the sources of Catholic doctrine in this area, largely the writings of the Popes, give no hint that government workers are to be considered an exception. While it is true that taxpayers fund the wages and benefits of public employees, the status of taxpayer does not entitle one to be an unconscionable employer. Government agencies draw from the same pool of surplus labor as do private companies, and the downward pressure on wages is the same.
From the foregoing it should be clear that the conditions of working people are not peripheral to Catholic social doctrine, but central and foundational to it. Those who consider the rights of working people as secondary concerns or who oppose labor unions are opposed to the social doctrine of the Catholic Church, regardless of how they present themselves.