Current and former Trump officials say Trump can react volcanically to negative press clips, especially those with damaging leaks, becoming engrossed in finding out where they originated.

That is what happened in late February when someone mischievously gave the president a printed copy of an article from GotNews.com, the website of Internet provocateur Charles C. Johnson, which accused deputy chief of staff Katie Walsh of being “the source behind a bunch of leaks” in the White House.

No matter that Johnson had been permanently banned from Twitter for harassment or that he offered no concrete evidence or that he had lobbed false accusations in the past and recanted them. Trump read the article and began asking staff about Walsh.