It’s important to understand the political climate before the NY State legislature decided to pass Hecht-Calandra in 1971. The New York Times does a great job filing in that context.
In 2016, a proposal to send some Upper West Side children — who were zoned for a high-performing, mostly white,
wealthyelementary school near their homes — to a lower-performing school, attended mostly by low-income black and Hispanic students, about a ten-minute walk away, was met with vitriol.
A version of the plan — which ultimately impacted a relatively small number of schools — eventually passed after years of negotiations.