there is less and less upward mobility in this country.
There is a lot of truth to this statement but the important question is why. You try to tag it to Reagan but I would argue it actually started after he left office and gained momentum under Clinton with NAFTA, aka Ross Perot's "great sucking sound as jobs left US, unfair trade deals with China et al that hollowed out our manufacturing sector, vastly increased immigration, legal and illegal, which put downward pressure on salaries( which is the point of it after all), Fed and government policy that rewarded and bailed out Wall Street but screwed small savers, and the obscene increases in CEO and other high level compensation.
Another factor clearly is affirmative action, which disproportionately impacts smart but poor white kids in getting into universities. The elites take care of their own. They could give a shit about anyone else, but they make a show of obsessing over POC, immigrants etc. Why not? They're not the ones paying the price for it.