What you're saying would make more sense if we were talking about a few years after the war, but the trend I'm referring to continued for decades after the war,

What you're saying would make more sense if we were talking about a few years after the war, but the trend I'm referring to continued for decades after the war, well into baby boomers entering the workforce as a massive generational force. And yes, I am literally saying that decades of policy has had an effect on this, and that it's not just a recent issue. Decades of anti-tax policy has created an environment where wage growth is difficult if not impossible for most people, immigrants or not, and decades of anti-immigration policy has helped create a situation where most immigrants aren't in a position to demand fair wages to begin with.