For the past dozen years, charter schools have been the golden children of Mayor Michael Bloomberg. He gives them free space in public schools; he trumpets their superiority; he attends their functions; he constantly reminds the public that charters are far, far better than the public schools that he is directly in charge of.

A paradox, is it not? In one night, the Robin Hood Foundation raises $80 million for…what else? charter schools.

Charter schools get more money than public schools. Many have billionaires on their board of directors. Some charter leaders are paid close to half a million a year to oversee a small number of students. Charters take far fewer English learners and students with disabilities compared to their neighborhood schools. NYC charters have high turnover of teachers because the hours are long, and endless test prep can be a drag. Some have very high scores, some get low scores. When the Common Core test results came in not long ago, the charter scores fell harder than the public schools.

The charters enroll only about 5% of the city’s 1.1 million children, but they certainly have had a privileged role in the eyes of the mayor, the business community, and the media.

But the charters are terrified of Bill de Blasio, the Democratic candidate for Mayor, and the likely next mayor. Yesterday some closed their schools to lead a political march across the Brooklyn Bridge, an act that would have been illegal if they were public schools.

This is why de Blasio frightens them. He has said that he will charge them rent if he is elected mayor, for use of public space. He has said he will put his emphasis on building the traditional public schools, where 95% of the children are enrolled.

Imagine that! What an innovative idea! Trying to improve the schools that enroll 95% of the children instead of pampering the ones that enroll 5%.