Billionaire Paul Singer, who is endorsing Republican presidential candidate Sen. Marco Rubio (R-FL), is a supporter of the Common Core standards and his foundation has been a donor to the heart of former Florida Gov. Jeb Bush’s education empire: the Foundation for Excellence in Education.

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.”

“The Foundation seeks to leverage its own philanthropic investments by partnering with proven non-profits and like-minded donors,” states the Singer Foundation website.

Despite Singer’s clear support for Common Core, Rubio and his team maintain the Senator is opposed to Common Core. “Marco has opposed common core for years, and will continue to oppose it as president,” Rubio spokesman Alex Conant told Breitbart News on Tuesday afternoon.

Conant also points back to what Rubio said about Common Core in the GOP debate hosted by the Fox News Channel back in August in Cleveland, Ohio.

In that debate, Rubio bashed Common Core. “The Department of Education, like every federal agency, will never be satisfied,” Rubio said about the federal education bureaucracy. “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,” Rubio continued in his comments during the debate. “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.”

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).

One group that is an affiliate of FEE is Chiefs for Change – a “bipartisan coalition of current and former state education chiefs who believe that American public education can be dramatically improved.” Some “Chiefs for Change” are also members of the Partnership for the Assessment of Readiness for College and Careers (PARCC), one of the two federally funded interstate consortia that have been developing tests aligned with the Common Core standards.

Additionally, Bush joined with former president of the pro-Common Core Fordham Institute Chester Finn and the U.S. Chamber of Commerce in Conservatives for Higher Standards, a group that promotes the Common Core standards initiative.

FEE’s donor list also includes the Bill and Melinda Gates Foundation, the GE Foundation, the Helmsley Charitable Trust, News Corp, the Walton Family Foundation, Bloomberg Philanthropies, Carnegie Corporation, the Schwab Foundation, Microsoft, Exxon Mobil, Houghton Mifflin Harcourt, Intel, K12, Pearson, Scholastic, and Target.

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.”

After citing realistic concerns about American students’ stark lack of knowledge about civics and U.S. History, Sahm then wrote:

One hopeful development is the Common Core State Standards, which have been voluntarily adopted by 45 states and the District of Columbia. Although the standards focus solely on English and math, the English standards call for students to analyze and understand some of the foundational documents of American history, including the Gettysburg Address. The Gilder Lehrman Institute of American History, a nonprofit devoted to improving history education, has a new Common-Core-aligned “Teaching Literacy through History” program that helps teachers expose students to these documents in a substantive way. Lesley Herrmann, executive director of Gilder Lehrman, noted in a panel discussion last week that teachers are hungry for good content with which to implement the Common Core. In fact, the organization’s website is receiving over 80,000 visits each week.

Then, in April of 2014, Sahm continued at The Daily Beast by claiming, “An unholy alliance between the Tea Party and the teachers’ unions threatens to derail the most promising education reform in decades.”

Referring to opposition to the Common Core as “hysteria,” Sahm wrote:

But most of the assault on the Common Core is based on a fundamental misunderstanding: The Common Core State Standards are not a national curriculum. They are just a basic outline of what students should be learning in math and English at each grade level. It is up to local superintendents and principals to select curricula that comply with the standards. If one takes the time to actually read the standards, it is hard to find anything controversial in them. For better or worse, the standards are not very prescriptive…

But so much of the backlash against the Common Core is built on misinformation. As David Brooks pointed out in The New York Times the other day, the ideological circus has descended and a perfectly sensible if slightly boring idea is being buried by hysterical claims and fevered accusations.

Although the Common Core is battered and bruised, one hopes that the quiet and reasoned arguments of the sensible center will prevail and the nation won’t lose this historic opportunity to provide American students with a more rigorous, content-rich, cohesive K-12 education.

Most recently, Sahm wrote in June at the Daily News that Common Core gets “high marks” in New York City:

So how are New York City schools doing at getting quality materials into classrooms to help implement the Common Core? A new paper by the Manhattan Institute, based on focus groups and an online survey, indicates that the news is mostly good: New York City has taken the Common Core adoption seriously, and — notwithstanding the recent controversy over the state tests and their use in teacher evaluations — the curriculum-implementation process has been successful…

Charter-school leaders are also taking Common Core implementation seriously and focusing more on curriculum. Many acknowledged that the challenging new Common Core-aligned exams have increased the need for quality curricula and rich academic content.