Just about anyone who opposes the Common Core national curriculum standards, currently under serious fire in New York, is either a kook or a self-interested schemer. That, at least, is the impression an impartial observer would get from listening to many Core supporters. But the reality is quite the opposite: Education thinkers from across the political spectrum are taking on — and apart — the Core.

In the Empire State, education commissioner John King infamously declared parents and concerned citizens opposed to the Core “special interests.” He made the accusation as he cancelled a series of town hall-style meetings scheduled across the state. After major blowback, he scheduled new events, but the message King delivered was clear: Many Core opponents only care about themselves, not kids.

Alas, this marginalization strategy is not confined to New York. Former Florida governor Jeb Bush, arguably the Core’s greatest champion, has accused Core opponents of employing conspiracy theories. And, in an op-ed being shopped to outlets around the country, Michael J. Petrilli and Michael Brickman of the Thomas B. Fordham Institute characterize Core opponents as a “small but vocal minority of conservatives” coupled with a bit of “the far left.” Read: scary fringe types.

Of course there are some Core opponents who say outlandish things, but that is the exception, not the rule. And much more important is a diverse group of people opposing the Core who are the exact opposite of the schemer stereotype: education experts.

The Common Core is opposed by scholars at several leading think tanks on both the right and left-hand side of the political landscape, including the Heritage Foundation, The Hoover Institution, the Brookings Institution and my own Cato Institute. My research has shown that there is essentially no meaningful evidence that national standards lead to superior educational outcomes.

Hoover Institution Senior Fellow Eric Hanushek, a well-known education economist and supporter of standards-based education reform, has reached a similar conclusion about likely Core impotence. He recently wrote: “We currently have very different standards across states, and experience from the states provides little support for the argument that simply declaring more clearly what we want children to learn will have much impact.”

Hanushek’s conclusion dovetails nicely with Common Core opposition from Tom Loveless, a scholar at the left-leaning Brookings Institution. In 2012, Loveless demonstrated that moving to national standards would almost certainly have little, if any, positive effect because the performance of states has had very little connection to the rigor or quality of their standards, and there is much greater achievement variation within states than among them.

In fact, Loveless has been one of the clearest voices saying the Core is not a panacea for America’s education woes, writing: “Don’t let the ferocity of the oncoming debate fool you. The empirical evidence suggests that the Common Core will have little effect on American students’ achievement. The nation will have to look elsewhere for ways to improve its schools.”

Moving to arguably the far left, prolific education historian Diane Ravitch has also taken on the Core, noting that it is untested, was assembled behind closed doors, and was essentially foisted on schools by the federal Race to the Top funding contest. That it also seems intended to produce huge increases in test failures — as occurred when New York employed Core-aligned tests without Core-aligned curricula — seemed to push Ravitch over the edge.

“This is what we know: the Common Core tests cause a huge decline in test scores. Passing rates fell 30 percent in Kentucky and about the same in New York,” Ravitch wrote on her blog recently. “Where are we heading? It won’t do to keep saying, as [U.S. Education] Secretary Duncan likes to, that only extremists oppose the standards. Reasonable people question them as well.”

There is an extremely well-informed opposition to the Core, and dismissing opponents as loony or selfish does New York’s children no service.

As Commissioner King picks up his statewide Core tour, he owes it to the kids to seriously contemplate the massive evidence against his favored reform.