The contemporary Left is postmodern. Postmodernists say there are no values (or that there can be no hierarchy of values). So isn’t it an oxymoron for someone to say that they have Left-wing values? Wouldn’t this come into conflict with their postmodernism?
Of course, this is an issue not just with the postmodern Left, but with the postmodern Right as well. You may recognize the postmodern Right by another name: neoliberals.
Our contemporary culture is dominated by anti-value postmodernism. And Trump is the President of that movement. He is everything the postmodernists, Left and Right, have been saying they wanted. But now that they have him, we get the same old aw: “But that’s not what we meant!” Of course it’s what you meant, just like Stalin is what Marx meant. Fortunately, postmodernism has no principles with which to justify directly murdering millions, so there is that.