Elizabeth Stoker Bruenig makes the case in Dissent:
Viewing the relationship between Christianity and leftism as inherently antagonistic is firstly a disservice to history. Despite the efforts of the business leaders who conquered Christian thought during the Great Depression, American Christians have never supported capitalist domination of governance or of society. Consider, for instance, a recent study by historian Heath Carter of the Christian roots of labor union organizing in Chicago during the Gilded Age. In Union Made: Working People and the Rise of Social Christianity in Chicago, Carter recovers what has been lost to the rhetoric of the Christian right, namely that Christianity (even its evangelical iterations) aligns very well with the goals of organizers fighting for justice and dignity in their work. Indeed, America’s labor movement has long enjoyed support from Christianity of all stripes, from the Catholicism of Dorothy Day and the Catholic Worker, to the peace-oriented Protestantism of A.J. Muste and the Society of Friends.
Outside of labor organizing, Christian theology has also influenced other leftist social movements, such as black power in the United States and liberation theology in Latin America. American civil rights activists like Martin Luther King, Jr. invoked this theology of liberation to agitate not only for racial justice, but for equality everywhere and for everyone, including in the sphere of economics. Today, the same line of reasoning is evident in the words and writings of Pope Francis, who has added environmental concerns to the issues we must address so that all can flourish equally.
Christianity, in other words, is no more destined for a cozy relationship with neoliberal, free-market politics than any other ideology, and perhaps less so, given its longstanding interest in the poor. The fact that Christianity is reflexively associated with conservatism in the United States is not so much an accident of history as it is a concerted effort on the part of vested, moneyed interests.