These schools have given thousands of low income minority children their only shot at a decent education, which often means their only shot at a decent life. Last year 82 percent of the students at a charter school called Success Academy passed city-wide mathematics exams, compared to 30 percent of the students in the city as a whole.
Why would anybody who has any concern at all about minority young people -- or even common decency -- want to destroy what progress has already been made?
One big reason, of course, is the teachers' union, one of Mayor de Blasio's biggest supporters. But it may be more than that. For many of the true believers on the left, their ideology overrides any concern about the actual fate of flesh-and-blood human beings.
Something similar happened on the west coast last year. The American Indian Model Schools in Oakland have been ranked among the top schools in the nation, based on their students' test scores. This is, again, a special achievement for minority students who need all the help they can get.
But, last spring, the California State Board of Education announced plans to shut this school down!
Why? The excuse given was that there had been suspicious financial dealings by the former -- repeat, former -- head of the institution. If this was the real reason, then all they had to do was indict the former head and let a court decide if he was guilty or innocent.
There was no reason to make anyone else suffer, much less the students. But the education establishment's decision was to refuse to let the school open last fall. Fortunately a court stopped this hasty shut-down.
These are not just isolated local incidents. The Obama administration has cut spending for charter schools in the District of Columbia and its Justice Department has intervened to try to stop the state of Louisiana from expanding its charter schools.
Why such hostility to schools that have succeeded in educating minority students, where so many others have failed?
Some of the opposition to charter schools has been sheer crass politics. The teachers' unions see charter schools as a threat to their members' jobs, and politicians respond to the money and the votes that teachers' unions can provide.
The net result is that public schools are often run as if their main function is to provide jobs to teachers. Whether the children get a decent education is secondary, at best.
In various parts of the country, educators who have succeeded in raising the educational level of minority children to the national average -- or above -- have faced hostility, harassment or have even been driven out of their schools.
Not all charter schools are successful, of course, but the ones that are completely undermine the excuses for failure in the public school system as a whole. That is why teachers' unions hate them, as a threat not only to their members' jobs but a threat to the whole range of frauds and fetishes in the educational system.
The autonomy of charter schools is also a threat to the powers that be, who want to impose their own vision on the schools, regardless of what the parents want. Attorney General Eric Holder wants to impose his own notion of racial balance in the schools, while many black parents want their children to learn, regardless of whether they are seated next to a white child or a black child. There have been all-black schools whose students met or exceeded national norms in education, whether in Louisiana, California or other places around the country. But Eric Holder, like Bill de Blasio, put his ideology above the education -- and the future life -- of minority students.
Charter schools take power from politicians and bureaucrats, letting parents decide where their children will go to school. That is obviously offensive to those on the left, who think that our betters should be making our decisions for us.
(Daily Corinthian columnist Thomas Sowell is a senior fellow at the Hoover Institution, Stanford University, Stanford, CA 94305. His website is www.tsowell.com.)