.

“She has this unique position that she’s earned,” said former Gov. Chris Christie of New Jersey, who worked closely on the opioid crisis with Ms. Conway and credited her with urging the president to personalize the issue through his brother’s experience with addiction. “She’s gotten a bad rap at times, but I think that’s because of some of the really awful people inside the White House who have been trying to hurt her, as opposed to anything the press came up with on its own.”

In recent months, Ms. Conway has watched, somewhat from the sidelines, as John F. Kelly, the president’s current chief of staff, came in and pledged to bring order to the West Wing, dispatching a number of aides who had once envied the access Ms. Conway cultivated with the president.

“He came around and wanted to know what everyone had been working on for the first six months,” Ms. Conway said, “and some of us were just better equipped to handle that question than others.”