"Christian leftist" comes very close to being an oxymoron.
Left in politics indicates a predilection to socialistic policies, with an almost religious adherence to those ultimate goals. When this much religious fervor is poured into the mechanics of administration of social reformation, there is blessed little left to direct toward the salvation of men's souls.
Islam becomes merely a "moral equivalent" of Judaism or Christianity, which in the end, shall be equally despised by the dedicated socialist. But on the short term, the Left can make common cause with Islam, if that means hastening the end of dominance by Christian and Jews in Western elected representative republics.
There are two wars going on right now, one for the preservation of historical definitions of freedom and human dignity, and another for our very souls. We cannot afford to lose either.
I am currently re-reading C.S. Lewis's Screwtape Letters (a series of letters written by a devil to his nephew, a junior tempter).
One of the great letters is about co-opting Christianity to make it PART of a cause or a means to an end --- e.g., pacifism or, on the right social conservatism.
This effort reeks of using Christianity as such a tool.
Amazing book, really. Can read it in an evening, but I am savoring it.