It had been nearly six years since I’d spoken to McCain. The New York Times is not his favorite newspaper, to say the least. The flash point was an article the paper published in February 2008, which some readers took to imply that he’d had an intimate relationship with a Washington lobbyist, Vicki Iseman. Both parties denied a romantic involvement, and Iseman sued The Times. (Iseman ultimately dropped the suit after The Times agreed to print a note to readers saying the story was not intended to imply a romantic relationship.) The report was widely criticized, and McCain distanced himself from the paper’s reporters. “I will never forgive The New York Times for what they did,” McCain told me in October. He agreed to talk to me, he says, because he knew me before “that story” ran. I have a pre-existing condition.

After his screed on the floor against Harry Reid, McCain hurries back to his office for a scheduled sit-down with a group of dignitaries from Australia. “I love the Aussies!” he declares to me outside his office door, then swings it open and is met with a faceful of them. “Sorry I’m late,” he tells them. “I was just up on the floor kicking the crap out of the Democratic leader.” They all sit down, and McCain mentions that Congress’s approval ratings are now so low “we’re down to paid staffers and blood relatives.” He drops this line so often that probably the only people on the planet who haven’t heard it are in Australia. Everyone laughs, and McCain adds that he recently received a call from his 101-year-old mother, and she’s not happy with Congress, either. “So now we’re down to just paid staff,” he says, to genuine belly laughs. A few minutes later, McCain wants to talk about Fiji, the archipelago in the South Pacific where he says he used to vacation with his family. “They are lovely, gentle people,” McCain says of the Fijians, “even though they used to eat each other.”

On that note, McCain goes off to be interviewed by Wolf Blitzer of CNN from a remote studio on the Hill.

Blitzer, whose arching dome of white hair rests in perfect symmetry with the anchor desk’s Capitol backdrop, greets McCain off the air. “Woof, woof,” McCain says to the host while someone fastens on a microphone. Then he howls and grins and prepares to discuss the day’s “outright hypocrisy.”

It is well entrenched in the McCain mythology that he finished nearly last (894th out of 900) in his class at the Naval Academy and never set out to be a great American hero, let alone a politician. He fell into the role — out of an airplane. Politics caught him. He ran for the House in 1982 and then the Senate in 1986. Even then, he conveyed a sense that he didn’t need or especially want this job, but over the years he became essential to the scenery: the Sunday shows, the Senate fights, the high-level globe-trotting. The arena suited and needed and defined McCain. He often parks himself in a hallway at the Capitol and waits for reporters to surround him. He is proud to hold the record for most appearances — 69 — in the 66-year history of “Meet the Press” and also to have more Twitter followers than anyone in the Senate (1.85 million badges of his relevance — nearly four times as many as the next Republican colleague, Marco Rubio). You can call this vanity, self-celebration, whatever — if it were a crime, the Capitol would be empty. But in McCain’s case, it’s also proof that he was present and accounted for, which is perhaps no small thing when you spent a good portion of your life expecting to die in a P.O.W. camp. In McCain’s worldview, anonymity equals absence.

“I think the biggest fear John has is not being relevant,” Graham told me. “He worried after he lost the election in 2008. He worried, O.K., I’m done, nobody wants to deal with a loser.” McCain has a favorite line, one of his hundreds, which he attributes to the late Texas senator John Tower: “Don’t let your coattails hit you in the ass,” Tower told him once. “Keep moving.” To McCain, “keep moving” is both a credo and a coping strategy, a balm of perpetual motion and high demand. He likes to provide unprompted recitations of his packed schedule. I was sitting with him in his office in October, shortly after the government shutdown ended. He was, as he often is, fresh off a regimen of morning TV interviews — CNN, “Squawk Box.” “I did a bunch last night too,” he volunteered.

Even when sitting still, McCain projects stir-craziness. Lengthy Senate hearings can be a challenge for him. He was recently busted in a photograph playing video poker on his iPhone during a hearing on Syria. (“Scandal!” he tweeted. “Caught playing iPhone game at 3+ hour Senate hearing — worst of all, I lost!”)