As he ends his first year in office, Mr. Trump is redefining what it means to be president. He sees the highest office in the land much as he did the night of his stunning victory over Hillary Clinton — as a prize he must fight to protect every waking moment, and Twitter is his Excalibur. Despite all his bluster, he views himself less as a titan dominating the world stage than a maligned outsider engaged in a struggle to be taken seriously, according to interviews with 60 advisers, associates, friends and members of Congress…

Before taking office, Mr. Trump told top aides to think of each presidential day as an episode in a television show in which he vanquishes rivals. People close to him estimate that Mr. Trump spends at least four hours a day, and sometimes as much as twice that, in front of a television, sometimes with the volume muted, marinating in the no-holds-barred wars of cable news and eager to fire back…

To an extent that would stun outsiders, Mr. Trump, the most talked-about human on the planet, is still delighted when he sees his name in the headlines. And he is on a perpetual quest to see it there. One former top adviser said Mr. Trump grew uncomfortable after two or three days of peace and could not handle watching the news without seeing himself on it.