White House senior adviser Dan Pfeiffer announced Wednesday he will be leaving the administration in early March, NBC News reported. He was part of then-candidate Barack Obama's senior campaign circle in 2008 and is the president's longest serving staffer. Pfeiffer is currently leading an internal review of how the White House should communicate using different platforms."Dan has been beside me on every step of this incredible journey, starting with those earliest days of the campaign in 2007," Obama said in a statement. “He's a good man and a good friend, and I'm going to miss having him just down the hall from me."