special counsel robert mueller examine role former national security adviser mike flynn may effort obtain hillary clinton email russian hackers wall street journal report friday efforts seek hackers steal email former democratic presidential candidate hillary clinton lead republican activist peter smith journal say mueller appoint special counsel determine whether collusion president donald trump 2016 presidential campaign moscow flynn resign february revelations discuss u.s. sanction russia russian ambassador unite state trump take office mislead vice president mike pence conversations representatives white house mueller office could immediately reach comment robert mueller examine flynn 's role seek clinton email hackers wsj