(who cited Theodore Dalrymple)
Common denominator? NO HUSBANDS.
The most important variable is the presence of a biological father at the breakfast table. Why that is so is not a political or even a moral question, it is something hard wired. He does not have to be Father of the Year. He can sit there in his underwear and grunt but for some reason his mere presence gives the child a sense that there are rules and structures and an order to the Universe. It is like Genesis, you start by drawing the boundaries and then the entire structure can be attached to that. Individuals can be socialized and taught to be successful if they lack that initial condition but groups cannot. Daniel Patrick Moynihan laid out decades ago how well intentioned social policies destroyed minority communities.
The damage can happen to all social and ethnic groups. For example I once taught at high school for the Talented and Gifted where some of our students came from solidly middle class homes. Those white children could get into trouble for the same reasons as the impoverished minority or recent immigrant kids. If both parents are lawyers working 90 hours a week then the child may feel like an orphan. Once you have to explain to a high powered mother that her daughter Laura has gotten the nickname "Oral" priorities get reexamined. The difference for the wealthy family is that they have more choices, they have the design margin to change and recover. The poorer, usually minority family, does not.
I have called the trapping of minority children in government run schools to serve the interests of the teacher's union a 13th Amendment issue. They are being held to involuntary servitude for the profit of others. If we just rounded up groups of adults based on some arbitrary category and corralled them into labor camps to make factory goods for the profit of Goldman Sachs and an oligarchic elite the violation would be clear. That does not happen much in America but we have off loaded the practice and it happens in China. In America the difference is that the factories do not even produce shoes and toasters but unemployables and the profits do not come from eager consumers but reluctant taxpayers.
The long term solution is not in the Charter schools, although the unions rightly fear them and all competition, but in vouchers. The unions try to destroy Charters, they barely tolerate competition from parochial schools and I suspect that much of the impetus to destroy the Catholic Church over the horrors of the child abuse scandals is motivated by left wing desire to eliminate an alternative educational structure, and they even try to expand district boundaries and deny people the right to vote with their feet and flee from the urban districts. The left wants to force people back into the cities where they can be controlled. The hostility to the automobile and other environmental causes resonate with that interest.
Government should either provide direct vouchers or tax credits for educational expenses, which is more efficient should be studied, and then inspect the schools and arrest those who take the money fraudulently. Government can do that effectively and if there are competing levels and agencies conducting the inspections then we could expect both many tabloid ready scandals and better educational results than in the present system.