Some officials said that Matt Whitaker, Attorney General Jeff Sessions' chief of staff, had told people he would be taking over for Rosenstein - an indication that the deputy attorney general's departure was all but certain - and were surprised when it was announced that Rosenstein would remain in his job. Sessions began telling people on Sunday that Rosenstein might be in trouble, according to people familiar with the matter. Others said they learned all the developments from news reports that evolved throughout the day.