There is a rather good article in the Guardian about Christian Democracy. Yes, really. Specifically, the authors wish to talk about the political situation in America, but in passing they define Christian Democracy as having three core principles:

The first is that the Christian tradition of natural law implies a commitment to the idea of the inherent dignity of the human person, which in turn sustains certain fundamental moral commitments – for instance, to the sanctity of human life, the importance of the traditional family and, more generally, moral authorities to guide human conduct. The second is a moral critique of capitalism based on the assumption that Christianity is incompatible with materialism and commands a duty of charity towards the poor and needy…. Finally, the third core principle of the Christian democratic ideology is a resolute internationalism, which translates into a commitment to both supranational cooperation amongst established powers and a duty of solidarity with respect to less fortunate peoples and countries.