His long tenure as education secretary means that he is one of only two of Obama's original cabinet appointees remaining.
When appointed in 2008, he was considered one of Obama's closest allies, often showcasing the skills he learned as the star basketball player at Harvard, and professional basketball player in Australia, in pick-up games against the president.
Over the past seven years, his initiatives have had a tremendous impact on educational policy, causing massive shifts in many states' educational systems.
Duncan's first year in office began, with reports of him being an exceptional figure and implying that we would be one of the most powerful secretaries of education in history.
That power came thanks to stimulus funds carved out for Duncan's education reforms following the 2008 recession.
Duncan, along with Obama, unveiled a competition that had states vie against one another for $4 billion in federal funds. That competition, called Race to the Top (RTTT), would become one of the seminal policies initiatives of his career.
Through RTTT, the federal government awards money states that agree to meet certain educational requirements set forth by the Department of Education, such as adopting the Common Core State Standards, linking teacher student performance to teacher evaluations, and allowing for the expansion of charter schools.
It was a bold plan which intended to spur innovation in the staid world of K-12 education reform, and was largely seen as an incredibly exciting moment in education, where states could take hold of their destiny and overhaul their current education system.
Hestoft-Pool/Getty Images)
If changes to states' education systems were the only yardstick to measure accomplishment, than Duncan could certainly claim success. In all, 18 states and the District of Columbia were awarded grant money from RTTT. And 46 states and DC dropped their prior standards to adopt the Common Core.
Success, however, is not that easy to measure. Though at the time RTTT was viewed positively, many outcomes from the competition are now highly criticized.
The biggest criticism is over the mass adoption of the Common Core. The Common Core State Standards are a controversial set of nationwide education standards developed in 2009 through a joint effort between state leaders and private Washington groups with the intent to strengthen standards and improve learning outcomes of students across the US.
But they are now a buzzword for ineffective standards and failed implementation. And critics also say RTTT money was dangled in front of states that were in desperate need of money following the financial crisis, in essence strong-arming them into change.
Lawmakers on both sides of the aisle have distanced themselves for the Common Core.
AP
NCLB is the law that was enacted, by then President George W. Bush, as a reauthorization of the Elementary and Secondary Education Act in 2002.
Duncan inherited the problem of dealing with NCLB, largely also seen as a failure. It's now been discredited to the point that almost all states now receive waivers that allow them to miss key elements of the law without any punishments. Duncan had the power to decide whether a state was granted a waiver or not, and used teacher evaluations linked to student performance as one criterion for a waiver.
Finally, the reach of charter schools have expanded in the seven years since Duncan assumed office. Much of that is, again, due to RTTT which made states agree not to have prohibitive laws in place to restrict charters.
An education reporter for the Washington Post, Lindsey Layton, argued that Duncan's role in history is even more important, claiming he changed how American's view charters. "The result is that most Americans now accept public charter schools as an alternative to neighborhood schools," she wrote.
But even his record on charter schools is highly contested by some of the most respected names in education reform. Diana Ravitch, wrote that "It will take years to recover from the damage that Arne Duncan's policies have inflicted on public education."
She asserts that he funneled billions of dollars into the charter sector while never publicly saying "a bad word about charters, no matter how many scandals and frauds were revealed."