But would he be more effective there, or as Trump's Chief of Staff?  Traditionally the FBI Directors have all had legal backgrounds.  In order to run that department you have to be a lawyer. It falls directly under the Dept of Justice   27b4  for a reason. They enforce the laws. Flynn is not an attorney. But who knows. Just remember as Trump's C of S Flynn would not need Senate confirmation. FBI Director requires it, and that is where as a non-attorney he would have difficulties even with more Trump leaning senators recently elected.  Why put Flynn through a Kavanaugh battle after all he has already gone through. As WH C of S he gets to rehabilitate himself from all the destruction Mueller and the Dems did. He gets to have authority over them in many ways, and he gets to sit in on all the big meetings so he could properly advise the president and watch his back. No one is better equipped and more loyal.