The corporate reform movement has spun an elaborate narrative in which charter schools are the solution to our nation’s allegedly dreadful public schools. “Waiting for Superman” became their message, used to win new converts. And the Common Core tests were supposed to put the nail in the coffin, demonstrating the utter failure of public schools.

For the past several years, study after study has shown that charter schools o not get better test scores than public schools if they enroll similar students. But, the reformers say, New York City was the exception. There, reformers kept finding “miracle schools,” where every student succeeded. And the New York City Department of Education boasted about its careful screening process for selecting charter authorizers. Here, the reformers claimed, was the realization of charter superiority.

But the myth just exploded. The narrative is a hoax. The Common Core tests that were supposed to destroy public education devastated the charter sector. Stephanie Simon of was first to notice that some celebrated charters like KIPP and Democracy Prep did worse than the public schools.

Now Gary Rubinstein examined performance for all charters in New York City and determined that the sector as a whole did worse than public schools on the Common Core tests.

In fact, the score collapse of the charter sector dwarfed that of the public sector. Gary writes:

“The most stunning example is the famed Harlem Village Academy which had 100% passing in 2012, but only 21% passing in 2013 for a 79% drop (you can see that sad dot all the way at the right of the scatter plot). Democracy Prep Harlem Charter, run and staffed by many TFAers, dropped 84% in 2012 to 13% in 2013. KIPP Amp dropped from 79% in 2012 to just 9% in 2013. The Equity Project (TEP) which pays $125,000 for the best teachers had finally gotten some test scores they can brag about with 76% in 2012, but that has now sunk to just 20% in 2013. The Bronx Charter School Of Excellence, which recently received money from a $4.5 million grant to help public schools emulate what they do, dropped from 96% in 2012 to 33% in 2013. So these are the schools that are the red ‘outliers’ hovering near the bottom right of the scatter plot. In general, the average charter school went down by 51 percentage points compared to 34 percentage points for the average public school. The most plausible explanation for charters dropping so much more than public schools is that their test prep methods were not sufficient for the more difficult tests. In other words “you’re busted.”

The reformer narrative just blew up.