I don't think that there is anything wrong with liberal progressive policies... which ones hurt individuals anyway? But yes, the break up of the traditional family unit has hurt society. The biggest thing to hurt children is discipline. Parents are told not to spank but don't know how to do the time out method properly because it is a skill, not something that you can just do. Gangs. Thugs. Hip hop culture. Kids suing parents. It is just a mess and comparing our education system to others is unfair. Our top kids are still top or more so, on the world stage.
New Zealand has a better ranked system than the USA. Society is pretty even in that most are European descendants. The Maori would be like our Mexicans, except a lot less of them. When Kiwis go to the USA for exchange they realize that they are, in general, behind. When American students go to New Zealand they realize that they are 1-2 years ahead of Kiwis even though the US system is supposedly behind. Why? Because gangs, non-English speakers, etc. are what is ruining the education system in the US... not the teachers. Not the curriculum.
When I taught in California I had two ELL Classes. English Language Learners. Nothing was learned in that class all year. I was teaching how to say door, or teacher. basic words. Students in that class didn't speak English and I spoke limited Spanish but I had an Israeli, a Pakastani (that sure made lessons fun!) a bunch of south of the border kids speaking various dialects of broken Spanish, three Vietnamese and a kid from Poland. They all took the same tests that the rest of the kids took but they all failed miserably and that brings down the over all score for the school, district, state and nation. Multiply this to every school and you see a massive problem. Then throw in gangs, ADD, social media bullying, etc and the political correctness bull **** (that is liberalism) that says all kids can be university students and all the other crap and we have problems that no teacher can ever hope to solve.