(CNN) To his supporters, he's the counterpuncher who won't relent in his own self-defense, even long after a perceived slight. To most everyone else, he's a begrudged bully who refuses to allow old vendettas to die — even after the foe in question has.

President Donald Trump has waged scores of feuds over his decades in public life, each singular in the minute details that irritate and consume him. But patterns have emerged that tie the conflicts together into one prolonged occupation Trump has honed over time.

This week, Trump railed against the late Sen. John McCain and the husband of a top White House adviser. His attacks on McCain, who is venerated among Republicans and widely respected by Democrats, drew shock and anger. His rebuke of George Conway, the lawyer spouse of Kellyanne, prompted more eye-rolling.

Those around Trump said they aren't sure why Trump is re-litigating the disputes now, though offered plenty of theories. Some officials suggested he is trying to distract from the looming conclusion of special counsel Robert Mueller's investigation. Others said he is eager to reoccupy the news cycle after congressional rebukes and a white nationalist terror attack.

A prevailing theory is that he's just bored and eager to inject controversy into the late winter doldrums.

"I think it's stupid," Trump's onetime communications director Anthony Scaramucci said on CNN. "He wants to continue to do that, I'm saying very publicly that's an unnatural social act and it will turn people off eventually."

"I understand the point, I understand the grievance that the President is bringing up. But you're not scoring any points with anybody," Scaramucci said.

Whatever the cause, Trump's attacks largely obscured his intended policy message, which on Wednesday was meant to be a resurgence of manufacturing in the Midwest.

And they followed a pattern of behavior that Trump has developed and honed long before occupying the Oval Office.

The origin

Trump's grievances can begin anywhere, but more often than not, spring from a personal slight or insult. In the case of McCain, Trump has long questioned whether the senator — who was held as a prisoner of war in Vietnam for five years — should be categorized as a hero. He revived that skepticism in the early days of his presidential campaign when McCain suggested Trump "fired up the crazies" during a rally in Phoenix.

It was all downhill from there, with the seed of resentment growing as Trump saw various other acts as signs of duplicity and treachery. Even as other Republicans rushed to McCain's defense, occasionally rebuking Trump by name, he did not relent.

This week, his renewed ire appeared to be prompted by a Fox News interview that mentioned McCain submitted to the FBI an unsubstantiated dossier of information about Trump's ties to Russia.

In the case of Conway, the spark was weekend tweets questioning the President's mental state — a subject that Trump has shown sensitivity about in the past. In response, Trump deemed the spouse of one of his top advisers, Kellyanne Conway, a "husband from hell."

People who have worked or known Trump going back decades say it was rare for the brash businessman to put aside the type of insults that others might quickly write off. Instead, they fester for years or decades, emerging at sometimes unpredictable moments. That was the case in Trump's dispute with Rosie O'Donnell, with whom he clashed in the mid-2000s and later attacked on the campaign trail.

"Not only does he come back strong, but he comes back to try to tug at some emotional piece," said Jack O'Donnell, who worked with as a Trump casino executive but later had a falling out.

Dividing loyalties

Trump's practice of unrelenting criticism has a tendency to divide people: those who view the attacks as self-defense and those who view them as unnecessary browbeating. Often, the people closest to Trump are caught in between.

This week's examples have forced some of Trump's staunchest allies to pick a side — either the President or the people they love.

Sen. Lindsey Graham, who has emerged as Trump's closest ally in the Senate, was also McCain's best friend. The pair traveled the world together on official business. When McCain died last year, Graham lamented that "America and Freedom have lost one of her greatest champions."

He added, "And I've lost one of my dearest friends and mentor."

Seven months later, as Trump renewed his attacks on McCain for voting against a health care repeal measure, Graham defended his late friend. But he did not call out Trump by name. The tepid response reflected Graham's newfound reliance on Trump as a political ally, one he phones frequently and plays golf with on the weekends.

Long fixated on the loyalties of those close to him, Trump rarely forgets who was with him and who wasn't. His tests of allegiance have divided families and close friendships — something he watches play out with enthusiasm.

In the case of the Conways, Trump has injected himself into what was once a political disagreement between husband and wife. George Conway's tweets attacking the President and questioning his mental health have long bothered Trump, but he was advised to refrain from responding.

This week saw the end of the restraint. Trump labeled Conway a "wack job" on the South Lawn on Wednesday. But Kellyanne Conway — caught between a president she has served loyally and a husband intent on tearing him down — has shown no signs she'll step away from Trump.

Driving a wedge through relationships is a "way of control for him," said Jack O'Donnell.

"If he can cause more friction between the Conway family, I think that's what Trump is trying to do. And it's very typical of him," he said.

If the Conways' marriage finds itself split by Trump, it would not be the first time.

"I almost got divorced through this whole fiasco," Scaramucci said on Thursday. "Thank God my wife and I were able to put the marriage back together. I don't know why George is hitting him that hard. The President waited four months before he responded. And, you know, Kellyanne seems to be defending the President, so I want to stay out of that one because I don't like getting involved in people's relationships, particularly after the fiasco that I went through."