It doesn't work as it should.
What invaribaly happens in the state schools is that it becomes politically untenable to start firing out minroities in large numbers.
(Most of these kids are atstate schools; the article talks of the UC system.)
So remedial course work is introduced, to bring low-end students up to speed. Colleges are in effect doing what the high schools could not.
Two consequences:
1. taxpayers pay twice for the same service - a HS level education
2. Resources are diverted away from university education and university development.
Bad!