Arne Duncan's resignation will be met by a range of reactions, as he was well liked among the Obama Administration and heavily criticized by student loan borrower advocates.

According to The Washington Post, President Barack Obama and others close to the situation were apparently unprepared for Duncan to announce his resignation. Duncan was named Education Secretary in Jan. 21, 2009, shortly after Obama took office and has since become one of the President's longest-serving Cabinet members.

Before heading up the Education Department, Duncan served as the CEO of Chicago's Public Schools, Obama and Duncan's shared hometown.

"He's done more to bring our educational system, sometimes kicking and screaming, into the 21st century than anyone else," The President said during remarks at the White House on Friday. "America will be better off for what he has done."

Duncan is most known for increasing the federal government's involvement in education policymaking. While his supporters call this dedication to improving the nation's public schools, his critics say he is doing more harm than good.

"Secretary Arne Duncan liked to describe the U.S. Department of Education's policies as 'game-changing'. Nearly seven years and hundreds of billions of dollars later, the data demonstrate that his efforts were anything but effective at improving student achievement," Jim Stergios, executive director of the anti-Common Core Pioneer Institute, said in a statement obtained by The Post. "His thin record delivering results for students is evident in our NAEP scores and performance on international tests. The School Improvement Grant program and reform agenda for colleges achieved little."

But Duncan always had Obama's support, and the two worked closely together on the divisive College Rankings system. The Post also noted that the two families were close and often spent time together on weekends and various holidays.

Obama named John King Jr. Duncan's successor to run the Education Department throughout the remainder of his Presidency, The Associated Press reported. While King's tenure appears to be permanent, it will be in an interim capacity to avoid going through the Senate for a formal nomination.

"Arne Duncan has been one of the best Secretaries of Education in our nation's history.  Over the past 7 years, he has been a dynamic leader who brings unparalleled energy to his work," Vice President Joe Biden said in a statement. "During his time as Secretary, Arne has made almost unprecedented strides in changing the direction of education in this country through his work to improve graduation rates, expand access to community colleges and raise academic standards for students all across the country. He has also done tremendous work through Title IX to make campuses safer for women and girls.  He's a man of great character and principle and he has become a close friend to Jill and me.  We wish him all the best and we will miss him dearly."