There's a market failure here wherein firms don't invest in training because a trained worker can then easily leave, instead electing to only hire people who can already do the job (hence all the "entry level: 5 years experience required" postings). 
Note: all of these arguments are common in economics literature, just not typically presented to the public or used in the static models used to argue for free-trade agreements. Also note that these are actually args against *deindustrialization* not free trade per se.
In the same way that a country that receives immense quantities of free food is not likely to have a great agricultural sector, skilled immigration causes 'skill shortages' by reducing the incentive for natives to acquire said skills.
Then, between 2000 and 2007 US manufacturing employment really did collapse, across all subsectors, far more than in any other major economy. The number of manufacturing establishments also fell. 
They use this power poorly. For example, the EEOC requires employers hire criminals on the grounds that African-Americans are more likely to be criminals, therefore not hiring criminals is racist. 
api.omarshehata.me/substack-proxy…
The slave trade was not dying in America; instead imports continued to rise until it was banned in 1808. US became the largest reservoir of slaves in the New World because of high rates of natural increase. Slaves were best suited (vs free labor) to sugar and cotton. 
"Women without educational achievement have more than 4 children, women with more than 12 years of schooling have only 1. 
One of the special interests for labor migration in many countries is low productivity firms trying to avoid going out of business. An example: textile factories in postwar Britain recruiting Pakistanis. They phrase this as "labor shortages," but we don't have to listen.
From the 1930s to the 1960s, the Bronx was known for its tranquility, with children playing outside unaccompanied, bikes and scooters left unattended, and doors left ajar for fresh air (!). 
The author, Carl Hansen, moved from Omaha, Nebraska to DC to join the public school system there. He was shocked and horrified by segregation in DC, which he regarded as evil, and made up his mind to do all he could to oppose it. 
I'm sure everyone who follows me has seen the "Britain immigration charts" a few times, but I'll post them again here. Severe 21st century economic dysfunction, declining physical capital stock per person. 
Apropos of nothing: immigration lowers national IQ almost everywhere. 
The multiethnic nature of Austria-Hungary meant that it could not separate domestic and foreign policy; every foreign issue had a domestic lobby and vice-versa. 
I think race (and ethnicity/LGBT - Mamdani's white support is probably ~50% Jewish and very gay) are much more salient to why Millennial socialism is a major political force than downwards mobility among elite. 
Unconditional surrender was publicly adopted as a war goal in Jan 1943, with the idea of preventing WWIII, as many Germans, including Hitler, thought Germany had not been beaten militarily in WWI and as such wanted to fight WWII. This caused trouble later. 
The genesis of the simultaneous Japanese attacks on Midway and the Aleutians Islands: the IJN had won so hard so fast (Pearl Harbor, Malaya/Singapore, Indian Ocean raid, Philippines, Dutch East Indies), they didn't have any obvious next thing to do. 
