The Obama administration can't seem to resist wading into state discussions about standards and tests, the guideposts that direct what is taught in local schools.

At issue is the Common Core State Standards Initiative, which seeks to set national criteria for instruction in English and math. The administration has tried to bribe states into adopting the national standards, using a pot of $4.35 billion in federal Race to the Top grants to sweeten the deal for those who go along. It also directly funded the national assessments that are aligned with the Common Core national standards, and it has tied No Child Left Behind waivers to adoption of the common standards.

For all that, the administration claims that any state decision to "participate" in the initiative is totally voluntary.

In recent weeks, Education Secretary Arne Duncan has tried to convince state leaders that the feds aren't even involved in the effort. But his doing so has ironically demonstrated just how much control the Department of Education stands to gain -- and how much states stand to lose.

Wading into South Carolina's debates on whether to adopt the Common Core national standards, Duncan issued a press release chiding the Legislature for briefly reconsidering its decision to adopt the national standards and tests. (South Carolina is sticking with them for the moment.) "The idea that the Common Core standards are nationally-imposed," Duncan wrote, "is a conspiracy theory in search of a conspiracy."

Like South Carolina, Utah has also been having second thoughts about ceding control of their educational standards to national organizations and Washington bureaucrats. Utah's Superintendent of Public Instruction, Larry Shumway, sent a letter to Secretary Duncan in early March asserting the Utah Board of Education's "right to complete control of Utah's learning standards in all areas of our public education curriculum."

Sec. Duncan's response to Shumway did not exactly inspire confidence. "Nothing in federal law or in current or proposed policies of the U.S. Department of Education in any way contradicts what is stated in your letter. States have the sole right to set learning standards," Duncan stated. "Thank you for the opportunity to clarify our mutual understanding."

Duncan is correct in reiterating that "states have the sole right to set learning standards." But he is incorrect in asserting that nothing in proposed policy "in any way contradicts" state control of curriculum.

As the Pioneer Institute recently reported, the U.S. Department of Education is running afoul of three laws prohibiting the federal government from being involved in curriculum. By funding the assessments and incentivizing states to adopt the Common Core with federal grants, Pioneer argues, the Department of Education "has simply paid others to do that which it is forbidden to do."

Over the last three decades the federal Department of Education's involvement in local school policy has increased in conjunction with its growing budget and program count. That expansion has been explosive under the current administration, and has been coupled with a gross disregard for the normal legislative process.

The federal government is indeed expanding, and the administration's coercive national standards effort is pushing legal limits.

The battle over national standards and tests is ultimately a battle over who controls the content taught in every local public school in America. Those fighting to regain control over standards and curriculum in state houses across the country are defending against a nationalization of education.

Secretary Duncan's robust involvement shows just how much control the Department of Education will gain if states surrender standards-setting control to Washington. Governors, state legislators, parents and taxpayers would be wise to resist those efforts.

Lindsey Burke researches and writes on education issues as a policy analyst at The Heritage Foundation.