Sam Harris is an interesting guy. Thanks for bringing him up. He's a cognitive neuroscientist which is a distinctively different creature, at least as much psychologist as anatomist. FWIW I agree with his view of the Abrahamic religions, or at least his view that they have been misused especially by myth-obsessed fundamentalists. My own view is that belief is fine and can be a very good thing. It's the certainty of the one true belief that causes problems in the world. In that regard, Muslims, Christians and Jews have more in common than they have separating themselves.
But to say that no one on the left appreciates the frictions betweem Islam and the West is just being silly. Obama for one has been quite articulate on this. The differences among intellectuals on the left and the right are in what prescriptions they would apply to resolve the frictions. To say it's a clash of civilizations is to overestimate the problem, I think. Obviously, Trump/Bannon don't. I think overestimating the size of the problem leads you to develop solutions that are ill-suited. We would never have invade Iraq, for example, if we had a properly scaled notion of what Al Qaeda was and what are abilities to effect change in the world were.
We're not going to solve the problems within Islam. In fact, much of what we do makes them worse, makes it harder for cooler voices within Islam to be heard and respected. I would include this immigration ban among them.