President Trump is shaking up his campaign staff, and he's turning to a former aide to New Jersey Governor Chris Christie.

Stepien was fired in the wake of the Bridgegate scandal, and although he denied any wrongdoing and was never charged, his name came up over 300 times in trial testimony. After leaving the Christie administration, he got a job in the Trump Administration, where he keeps a low profile and has become one of the president's longest serving and most powerful advisors. Now he'll be heading up President Trump's bid for reelection.