Mr. Trump has been uninterested in the campaign’s mammoth online advertising efforts, which have surpassed $4.5 million. When it comes to digital advertising in general, his response is to ask aides, “Is this for television?”

Unlike his last presidential race, during which Mr. Trump was concerned about spending because it was his own money on the line, he has not pressed for details. And he has made it clear that he does not relish participating in fund-raisers, leaving much of the donor maintenance and hand-holding to Vice President Mike Pence.

Mr. Trump may be indifferent to the mechanics of running a presidential campaign, in part because he continues to view his 2016 victory as driven almost entirely by his own force of personality and messaging.

“His counterintuitive gut instinct that drove much of the 2016 race was spot on through the primary and the general elections,” said Jason Miller, who served as a communications aide on Mr. Trump’s 2016 campaign. “I wouldn’t expect that to change going into 2020. He’s always going to be the one who drives the message and makes the important political decisions.”

Mr. Trump is also aware that his signature campaign promise — to build a wall along the border with Mexico — has not come to fruition. He has been looking for opportunities to demonstrate to his core voters that he is fighting to get it done, according to aides, and that he is being stopped by intractable political forces.

But many of his private, election-related conversations, aides said, tend to center on Mr. Biden.

In conversations with donors and allies, the president has continued to refer to him as feeble (Mr. Biden is 76; Mr. Trump is turning 73 this week) and noted that he was part of the Washington establishment, giving Mr. Trump the opportunity to run as the outsider even from his perch in the Oval Office.

“He views Biden as a failed vice president who’s going to be savaged by the left in the primary to the point of unelectability,” said Sam Nunberg, who worked on the 2016 campaign. “He also doesn’t believe he has energy.”