Though Marco Rubio has consistently opposed the Common Core standards initiative and its federal intrusion into an area reserved for the states by the Constitution, GOP rival Jeb Bush observed recently that Rubio once supported Race to the Top, the vehicle used by the Obama administration to incentivize states to adopt the education reform.

Bush, of course, has always been an avid supporter of Common Core, and Rubio has been slamming both him and Chris Christie about their advocacy for the federal education initiative.

In 2009, while Rubio was preparing for a Senate run, he responded to a question during an interview about Race to the Top – which was tucked into Obama’s stimulus bill, waiting to offer federal cash to states that would sign onto a set of uniform math and English academic standards, their associated tests, teacher evaluation plans, and massive student data tracking systems.

Rubio said, “Education is really in my mind a state function more than a federal one. I think the federal government complicates it.”

He then added:

I actually look at this Race to the Top – I don’t know how many of you are aware of it – that’s a program the president started to make money available to states who then have to go out and compete for that money by showing innovation. I don’t have a problem with that. I think that’s a good idea. But, by and large, I think that education is a state function, best regulated and governed at the state level.

I know, for example, No Child Left Behind is a well-intentioned piece of legislation. It’s had some unintended consequences. So, I really believe that the federal government should do as little as possible on the education front and empower the states – that’s really a state function.

Nevertheless, the Tampa Bay Times reports,  “That year, Rubio also praised Obama’s hire of Arne Duncan as education secretary, calling him an ‘innovator’ while praising the federal government’s effort ‘encouraging’ states to adopt curriculums ‘that reflect the 21st Century.'”

However, in 2011, now a U.S. Senator, Rubio wrote a letter to Duncan, expressing his concern about the Obama administration’s use of waivers to incentivize states to adopt the uniform standards and their associated policies.

The senator wrote:

Our principal concern is that the Executive branch does not possess the authority to force states into compliance with administration-backed reforms instituted through the issuance of waivers. We acknowledge that NCLB allows the Secretary to grant waivers for existing provisions under the law, but nowhere does the law authorize waivers in exchange for the adoption of administration-preferred policies. This initiative is an overstep of authority that undermines exiting law, and violates the constitutional separation of powers. The responsibility for legislating lies with Congress, and forcing policy reforms through NCLB waivers violates this most basic of constitutional structures.

Furthermore, I am concerned that the administration’s requirements for granting a waiver from NCLB would entail states having to adopt a federally-approved “college and career ready” curriculum: either the national Common Core standards, or another federally-approved equivalent. I am also concerned that the U.S. Department of Education has created, through its contractors, national curriculum materials to support these Common Core standards. Such activities are unacceptable; they violate three existing laws: NCLB, the Department of Education Organization Act, and the General Education Provisions Act. All three laws prohibit the federal government from creating or prescribing national curriculum. If you believe that conditional waivers tied to content standards do not violate these laws, I invite you to explain the reasoning underlying that belief.

Since legislating is a duty reserved for Congress, attaching administration-preferred reforms to NCLB waivers would counteract and inhibit meaningful education reform desperately needed to ensure that our children receive an education that will prepare them for the challenging global economic marketplace. I respectfully ask that due consideration be given to options that have been advanced through Congress and provide genuine flexibility to states, so that state and local lawmakers — those closest to children and families — can focus on high-quality education policies that will benefit our nation’s children.

However, Gary Fineout of Associated Press noted on Twitter Thursday, that while Rubio has been criticizing Jeb Bush and his support for Common Core, the Florida senator never asked state officials or Gov. Rick Scott to block its adoption.

Additionally, as anti-Common Core activists Florida Stop Common Core Coalition observed last November, Rubio received two donations to his 2011 and 2014 Senate campaign funds totaling $3,000 from Bill Gates – whose foundation has been the primary source of private funding for the Common Core initiative.

Breitbart News also previously reported that Rubio’s other elite sponsor – billionaire Paul Singer – is a major supporter of Common Core.

The report states:

Singer, who recently threw his support behind Rubio, founded the Paul E. Singer Foundation, whose work thus far has “focused on supporting research and scholars in the areas of free-market economics, the rule of law, U.S. national security, and the future of Israel, as well as LGBT equality efforts and health-care delivery innovation.”

In each year from 2009 through 2014, Singer’s foundation donated between $50,001-$100,000 to Bush’s Foundation for Excellence in Education (FEE).

Singer is also chairman of the pro-Common Core Manhattan Institute for Policy Research (MI). In November of 2013, Charles Upton Sahm, director of education policy at MI penned an op-ed for The Daily Beast titled, “How the Common Core Standards Can Help U.S. Students Understand History.”

Despite Singer’s clear support for Common Core, Rubio spokesman Alex Conant told Breitbart News in November, “Marco has opposed common core for years, and will continue to oppose it as president.” Conant also observed what Rubio said about Common Core during the GOP debate last August in Cleveland:

The Department of Education, like every federal agency, will never be satisfied. They will not stop with it [Common Core] being a suggestion. They will turn it into a mandate.

In fact, what they will begin to say to local communities is, you will not get federal money unless you do things the way we want you to do it. And they will use Common Core or any other requirements that exists nationally to force it down the throats of our people in our states.

“Although Rubio’s record is far better than Bush’s on the Common Core system, it is far from perfect,” asserts Dr. Karen Effrem writing at The Pulse 2016, where Rubio earned a grade of “C” on the Common Core Report Card.

Rubio’s mediocre grade was largely influenced by his support for the Know Before You Go Act, legislation that many education activists claim is simply a data-mining bill.

“This bill seeks to have the federal government collect data on students throughout their lives just to be able to provide information to others about which colleges and majors provide the best jobs,” writes Effrem.

In addition, Rubio has been an ardent champion on the campaign trail of vocational education – with some possible federal intervention. Voc ed training is also in keeping with the U.S. Chamber of Commerce’s goal of workforce development. The Chamber is a major supporter of the Common Core standards.

While Rubio has publicly opposed Common Core and federal intrusion of education over the last several years, some of his past views, recent donors, and support for data tracking, will likely draw concern from voters looking for greater consistency.