But in practical terms, he is under federal investigation. The question is whether he resigns in shame in the short term because he realizes he has no chance in 2016 (and whether Adelson has already promised him $100m to run), or whether he holds out until they threaten to charge him with something. (Or when they charge David Sampson.) Would Christie go through an entire trial without resigning? I suppose it's been tried. Would the state legislature allow him to do that without impeaching him?
Christie's term is not scheduled to end until January of 2018. It is obvious to all by now that he will take a swing at the Republican nomination for the 2016 Presidential election. Unless handcuffs are involved I do not see him resigning anytime prior to having wrapped up, at minimum, the Republican nomination.