The goal of government owned and union operated US schools is not education, it is Leftist indoctrination.
Those who think the goal of American K-12 education is to produce educated students also think the goal of the UAW is to produce fine autos.
Government schools were **always**, from there very beginning in the mid-19th century, a socialist scheme to produce compliant workers for the fascist state.
There was a another motivation as well: Virulent anti-Catholicism.
With the waves of Catholic immigrants streaming into the country nativists feared and hated the Catholics. Government schools at the time were essentially government supported Protestant indoctrination camps. If you do not believe this read some of the early textbooks. Even into the mid-1960s government schools had Protestant prayer and scripture reading. The Catholics fooled them, though. St. John Neumann set up a system of tuition-free Catholic schools.
Ah....But, those **foolish**foolish** Protestants failed to realize one thing:
Any government powerful enough to force Protestant Christianity on other people's captive children is powerful enough to force atheistic secular humanistic Marxism on their kids. The government can force them to pay for it, too! ( There are real bullets in those guns on the policeman's hip!)