The NAACP is against charter schools and American Federation of Teachers President Randi Weingarten has called them the “polite cousins” to Jim Crow. But new test scores released in New York indicate that black and Hispanic kids in Harlem are benefiting from the charter movement.

Eva Moskowitz, founder and CEO of the Success Academy Charter Schools, has looked at the new numbers. She writes in this morning's Wall Street Journal:

The results of the 2017 New York state tests were released Tuesday, and my staff has been busy crunching the numbers. They demonstrate how transformative [the growth of charter schools] has been for Harlem residents. In Central Harlem, for example, the number of students meeting rigorous, Common Core math standards has more than doubled since 2013—from 1,690 to 3,703. Students attending charter schools account for 96% of that growth. Results for English language arts are similarly inspiring.

The highest performing charter schools, like Success Academy, have actually reversed the achievement gap. Black and Hispanic students from Central Harlem’s seven Success Academy schools outperform white students across the city by 33 points in math and 21 points in reading; low-income students outperform the city’s affluent students by 38 and 24 points in math and reading respectively.

Moskowitz goes on to address the claim of anti-charter leaders that the charter movement has an adverse effect on public schools:

To justify their arguments, Ms. Weingarten and others propagate the myth that charter-school successes have come at the expense of traditional district schools. But this claim has been disproved again and again. In New York City, for example, a comprehensive study found improved academic performance, safety, and student engagement at district schools with charter schools, particularly high-performing ones, located nearby or in the same building.

This finding is exemplified by Harlem’s District 5. Charter-school enrollment in this district has grown exponentially since 2006, the year the first Success Academy opened. Far from spurring a decline among the district’s public schools, the district’s academic ranking relative to others in the city increased slightly over this period. When charter schools are included in this equation, its ranking spikes an additional 12 spots, from 14 to 28. Neighborhoods like the South Bronx and Central Brooklyn, where a growing proportion of students are attending charter schools, should expect to see similarly dramatic improvements.

Given this new data, it is hard to see the anti-charter arguments put forward by the AFT as anything more than a cynical campaign to hold onto union power–at the expense of low-income kids.