The problems with the Common Core are multiple. Many states are now experiencing a populist revolt against it, sometimes led by extremist groupss, sometimes (as in New York) led by responsible parents and veteran educators.

Support is strong and includes the Obama administration, major corporations, Republicans like Jeb Bush, and educators who like the new standards. Opposition is strong and spans the ideological spectrum, from parents who object to their complexity or to a federal takeover of standards to the Chicago Teachers Union and others who say the standards were developed in stealth, excluded classroom teachers and teachers knowledgeable about early childhood education and disabilities. Others are alarmed that the standards were pushed onto the states without discussion, without means of revising them, but as a condition of Race to the Top and waivers.

The battle over the Common Core has raged in several states. So e states has dropped their commitment to participate in the federally funded tests. At least one state–Oklahoma–wants to drop Common Core altogether.

What is the likely outcome of all this dissension?

No bold national idea has ever taken root in such contentious circumstances. For one thing, Common Core has thus far made its way based on promises, which may or may not be true. Will it raise achievement? Will it reduce achievement gaps? Will it prepare students to be college- and career-ready? Will it vault American students to the top of international competition? No one knows.

One thing we do know is that the transition to Common Core will be very expensive. Los Angeles, only one district, is spending $1 billion for iPads for Common Core testing. Common Core will be a bonanza for vendors but will bring with a high price that few districts or states can afford.

Given the controversy, which shows no sign of abating, and given the costs, what is the likely outcome?

Some states will drop the federal online testing. That is a good thing, because NAEP already provides state-to-state comparisons and has done so since 1992.

Some states will drop Common Core and use their old standards or write new ones. As Tom Loveless of Brookings has shown, standards don’t have a big effect; some states with high standards, like Massachusetts, still have big achievement gaps. Some states with excellent standards, like California, have low overall performance.

Loveless wrote in 2012:

“Similar stories can be told in many states. Standards have been a central activity of education reform for the past three decades. I have studied education reform and its implementation since I left the classroom in 1988. I don’t know of a single state that adopted standards, patted itself on the back, and considered the job done. Not one. States have tried numerous ways to better their schools through standards. And yet, good and bad standards and all of those in between, along with all of the implementation tools currently known to policymakers, have produced outcomes that indicate one thing: Standards do not matter very much.” He concluded: “On the basis of past experience with standards, the most reasonable prediction is that the common core will have little to no effect on student achievement.”

The likeliest outcome of the controversies today is that the Common Core will be adopted by some states, not by other. The federal tests will be used in some states, not others.

We are likely to end up with a natural experiment, in which we finally get the trials that the founders of Common Core preferred to avoid. We will be able to compare the progress of the states that are 100% Common Core aligned with other states.

The claims of the Common Core advocates will get an airing in real time, while those who oppose it will not be required to comply with its edicts.

And some day, maybe a decade from now, we will know more than we do today.