I'm not really even talking about classic liberalism, but the useful idiots are not even liberals by the standards of a few decades back. Heck, here you have in Islamism a religio-political ideology predicated upon the establishment of a rigid, regressive mindset that seeks to freeze society at a knuckle dragging, pre-enlightenment state where women are little but brood mares, freedom of speech is nonexistent, and other personal freedoms are so restricted that it truly does represent that "boot stomping on a human face forever" of which Orwell warned, but do any of the illiberal leftist apologists ever talk about that, much less criticize it? No, they seek to distract from it, they try to legitimize the mass murders carried out in the name of the ideology by referring to it as some sort of rational action and they do everything in their power to try to deny the link between ideology and action.
This does not just go against classic liberalism, but flies completely in the face of modern liberalism, too. Sift through the reams of grandstanding rhetoric, double talk and pseudo-intellectual babble, and you will find almost no actual criticism of the totalitarian ideology that drives the Islamists. What you will find is lots and lots of rationalization seeking to justify their actions. That is not liberal by ANY standard.