WASHINGTON — Relationships have always been President Trump’s currency and comfort, helping him talk his way into real estate deals over three decades in New York. Those who know him best say that his outer confidence has always belied an inner uncertainty, and that he needs to test ideas with a wide range of people.

As Mr. Trump’s White House advisers jostle for position, the president has turned to another group of advisers — from family, real estate, media, finance and politics, and all outside the White House gates — many of whom he consults at least once a week.

The media mogul Rupert Murdoch is on the phone every week, encouraging Mr. Trump when he’s low and arguing that he focus on the economy rather than detouring to other issues. The developer Richard LeFrak is a soothing voice who listens to Mr. Trump’s complaints that cost estimates for the border wall with Mexico are too high. Sean Hannity tells the president that keeping promises on core Republican issues is crucial.

Mr. Trump’s West Wing aides, like President Bill Clinton’s staff two decades before, say they sometimes cringe at the input from people they can’t control, with consequences they can’t predict. Knowing these advisers — who are mostly white, male and older — is a key to figuring out the words coming from Mr. Trump’s mouth and his Twitter feed.