How long before the reintroduction of segregation?

That does seem a natural extrapolation of this.

https://archive.is/cPjXx

Even after JFK's initiated reforms, quotas based on origins (birth county of future immigrants or birth country of existing immigrants in the US) is intact. If one sees this as a formula based on origins, some variables are changed after Immigration and Naturalization Act of 1965. So, it is very hard to get rid of origin and quota-based formulas. Now Trump wants to change some variables.