I agree with this completely. Knee jerk protectionism has never worked out well for the working class -- for every job it saves it just makes goods more expensive. On the other hand, the global uplift of globalism, which is real, is such a long term project (a century or more) that there needs to be a recognition that in the short term blue collar workers in rich countries have to have some other support, be it increased welfare, free education, reduction of wealth inequality, or all three. It doesn't help that the managerial and financial class that pushed globalism got INSANELY rich while working class Americans got screwed.
In the long run, a global working class with purchasing power, rights codified within a system of laws, and self-organized as a international labor force, was the dream of the Internationale. Globalism will get us there, but at the temporary (albeit long term) expense of the workers in rich countries. Enough surplus wealth is created by globalism to tide them over -- we just have to burn the plutocratic ticks off the economic body with re-distributive taxes so we can remove them with regulatory tweezers. The folks who run the world economy are obviously not interested in doing that, so the Pikettys and Warrens have to create plans and policies for liberal parties all over the world to promulgate. Bernie's 74, so he thinks reflexively that globalism is bad. Globalism can actually be good, as long as the profits are used to make the losers of the process (the workers in rich countries) whole again, and as long as we bend our economics towards egalitarian rather than elitist structures.