In both cases it's fallacious. How many "comfortable middle class" workers and in what fields are they? This isn't migrants it's the economic powers that be. Remember when America was the land of opportunity? You parents? Guess what, that's largely gone and illegals aren't the reason
Here is the US today. These numbers in essence show the odds of breaking out of the class one was born into. Billy Joel decades ago had the measure of this in "Allentown". Today doing as good as your old man did isn't nearly as likely and moving up? That's a bone that everyone ought to know is nothing more than a ploy. Hell, reviews are deliberately manipulated in many cases so those who deserve a raise don't get one, and the people in charge of that get a big bonus for not giving it to others.
But that chart- The lower number the higher your chances of advancement over you parents. We're crappy compared to those commie socialist nations, whose people aren't worn out and tossed for new fodder. We aren't dying because of McDonalds, we're not burning the candle at both ends, we're busting it up into a dozen pieces and burning all the ends. We've peaked on lifespan and are headed the wrong way. It's absolutely insane.
We're all living in Allentown and appeals to baseball, apple pies and sunny days with every Sunday off and having a "comfortable live" one could enjoy listing to the Beach Boys and other fantasies.
Moving to a two class society isn't a good idea and all the platitudes of Trump and the Republicans are self serving nonsense.