I keep a Wendell Berry poem at my desk with one particular line highlighted, "Be joyful, though you have considered all the facts." As far as I know Mr. Berry is on the Left politically, and a Christian.
I have also been obsessed with a neighbor's father, Raymond Bakke, from whose biography and lectures I have consumed started off Lutheran and became a Baptist minister. He also comes across as slightly politically liberal, in the demands of government money for the poor. But a lot of what he says about the urban church I agree with, for my own conservative reasons, such as programs and missions by the church should primarily be supported by the home church and not some outside entity.
There are hints that I do appriecate the political diversity of the Roman Catholic Church, though it is not all sunshine and roses. I find that the office of the Pope and the heiracrchy helpful in that the Church is not too apt to sway with the secular or other short term trends. So our sisters and brothers on the left do share communion with us and let their grievances be known, with out endangering the body of the Church. Unlike say, Protestant branches that break off and split, some easily, some with great and long pain and suffering, along secular party lines. There is a liberal strain of Catholic thought, pro-union and anti-loan (with calls to forgive national debit of 3rd world nations), that I don't agree with, but I see how a very liberal interpretation of the gospels can lead you that way.
Listening to some left leaning Christians, I do look for the centrality of Christ, and when finding him there, I'm set at ease and willing to hear the rest. Unfortnately, I've heard too many for whom the secular politics are a greater saviour. It is Christ who binds us, and as long as he is central left and right may come together.