The brightest jewel in the system of national testing is no longer in the crown. High-performing Massachusetts lent considerable luster to the national testing aligned with the national Common Core curriculum-content standards. Now, with a decision by the state’s board of education on November 17, it is gone. Many proponents of Common Core, including former U.S. Education Secretary Arne Duncan, had pointed to the adherence of Massachusetts to the Common Core as symbolizing the potential of the current effort to bring commonality to standards and tests. Massachusetts’s reputation for excellence boosted, by implication the reputation of Common Core. But now the state’s influential example will have the opposite effect. The withdrawal of Massachusetts now smooths the way for further states to leave.

In the face of the collapse of the national testing system, Common Core proponents have a reassuring message. Michael Cohen, the president of Achieve, a nonprofit that was a major player in the writing of the Common Core standards, has said that even though the national tests aligned with Common Core are now “toxic,” the Common Core standards themselves or something very like them were in place in most states, and that, according to Cohen, was the important thing.

The underlying message from proponents is that the Common Core standards are “world class” and so even if the testing system falls apart, it is worthwhile in itself to have installed the Common Core or near equivalents in many states.

But, first, the Common Core is not “world class.” All serious studies have found Common Core academically mediocre, trailing behind foreign high-achieving countries in the achievement it expects from students. Indeed, the sequence in which topics are taught in high-achieving countries varies widely. Singapore’s curriculum differs from Japan’s, which in turn differs from Hong Kong’s. Pretending that Common Core has succeeded in finding the unique and perfect combination of content and sequence is both foolish and arrogant.

The Common Core says to teach Algebra I in ninth grade (although high-performing countries teach it in eighth). It dictates how proof of the congruence of triangles should be taught in the classroom and requires that a method, known as “rigid motions,” be used—although that method has never been taught successfully in K-12 education in America. Parents have filled Facebook with examples of unnecessarily complex math methods using lattices and making tens. The Common Core English standards dictate the amounts of literary text (novels, poems, essays) versus informational text (Federal Reserve newsletters, edicts of the Environmental Protection Agency) that students should read in different grades.

Second, mediocre and rococo academics are only part of the reason for Common Core’s decline. Rather, what is noticeable is that states are abandoning Common Core’s goal of lock-step national uniformity. The Common Core imposes uniformity of subject-matter content across the states—content that is so much the same that any differences are insignificant. That nationwide uniformity was, according to the original plan, to be policed through national tests.

In 2010, Education Secretary Duncan told a group of education policymakers who were promoting a national curriculum that the national tests (whose creation his department was funding) would “help put an end to” different tests and different test-result expectations in the several states.

In the years ahead, a child in Mississippi will be measured against the same standard of success as a child in Massachusetts,” Duncan said.

But now the state boards of education in both Massachusetts and Mississippi have voted to withdraw from national testing consortia for all future exams.

Common Core’s goal was to have the whole country operate under uniform education standards, with two federally-sponsored and federally-monitored testing consortia policing compliance. And it anticipated having every student’s academic and demographic record available to the federal government to be used for workforce planning.

Third, near equivalents to Common Core will not function the same way as the original. Once the actual standards in force in the individual states are disconnected from central enforcement of Common Core though common tests, they will move farther from it over time. Many states have just changed the name of the Common Core—like Florida’s “Sunshine Standards” or Arizona’s “College and Career Ready Standards.” Their politicians think they can trick the public by changing only the name, but they forget that in a few years, when their own educators decide to eliminate some idiotic Common Core standard or move a topic to another grade, nobody will be able to argue that this cannot be done “because we are part of Common Core.”

Finally, states have been abandoning the national testing consortia in droves. When the consortia started in 2010, the Partnership for Assessment of Readiness for College and Careers had 26 members while Smarter Balanced had 31. This last spring 17 states administered SBAC and 11 plus the District of Columbia administered PARCC. Since then, the numbers for next spring already dropped to 12 for SBAC and six plus the District of Columbia for PARCC. In addition (or perhaps subtraction), Connecticut and New Hampshire have bailed out of SBAC high school testing for 2016. A lawsuit maintaining that SBAC is an illegal and unconstitutional inter-state compact has been upheld by both the trial and appeals courts in Missouri, and similar suits have been brought in Idaho, North Dakota and West Virginia.

Rejecting the tests is, in a sense, even more critical than rejecting the Common Core standards because the test is the only thing that actually enforces the standards. Without the tests, the standards can be adhered to in name only. When the states—rather than the consortia—control the test, they can easily modify the standards too. Moreover, by not participating in the federally-sponsored consortia, states do not automatically transfer their individual student data to the federal government in DC for workforce planning.

Within five years of their launch, Common Core’s mediocre academic standards are in shambles. States are running away from them, other states are trying to hide their participation in them by changing their name, and more than half of the states in the nation have abandoned the testing consortia—with more states showing signs of following them. Add this news to the fact that Massachusetts, the crown jewel of PARCC, has now departed. The death knell for Common Core standards and the associated tests is sounding.