President Trump has told close associates that he believes Steve Bannon is behind damaging leaks about White House colleagues, putting the chief strategist's job in fresh jeopardy, sources close to the president tell me. Trump has told associates he's fed up with what he sees as self-promotion by Bannon, who did not join the core team this week at the president's golf club in Bedminster, N.J. Bannon's time with Trump has diminished since the new chief of staff, retired Marine Gen. John Kelly, took over and imposed discipline on the circus around the Oval Office. Bannon declined to comment. Why...