They disappointed climate change activists who thought they would keep President Donald Trump from leaving the landmark Paris accord.

They enraged Democrats and even some Republicans by not pushing back against his immigration policies, and alienated business allies by their silence over threats to the North American Free Trade Agreement (NAFTA).

They regularly faced news stories about their unpopularity.

Even their relationship with the president seemed to suffer.

Several times Mr Trump joked that he “could have had (American football quarterback) Tom Brady” as a son-in-law. “Instead”, the president said, according to five people who heard him, “I got Jared Kushner”.

And yet, after 18 months of bruising internal White House conflicts and bitter criticism that they have failed to be a moderating influence on the president, both Mr Kushner and his wife, Ivanka Trump, the president’s elder daughter, are still in Washington and still working as aides to Donald Trump. They are as comfortable — and as close to the centre of his orbit — as they have ever been.

As scrutiny of the couple often referred to as Javanka became increasingly intense during the president’s first year, Mr Kushner and Ivanka Trump seemed to retreat from public view. And after several of their allies in the White House departed, there was a near-constant stream of questions about whether they would follow.

It did not help that the president had gone from telling aides to “talk to Jared,” as he did during the campaign, to telling them that “Jared hasn’t been so good for me.” At various points, Trump told friends and his chief of staff, John Kelly, that he wished both Jared and Ivanka would return to New York.

But as one staff member after another has disappointed him and has departed or been dispatched, Trump has retreated into the familiarity of his family — his daughter, above all, and eventually, her husband.

As Mr Trump, cut off from dissenting voices and convinced of his own popularity, has become more emboldened, so have his daughter and son-in-law.

It was only in May that Mr Kushner had his security clearance restored after months of questions about whether he was in peril in the investigation by the special counsel, Robert Mueller, into the Trump campaign’s ties to Russia. Mr Mueller’s investigators have not publicly cleared Mr Kushner, and Mr Kushner’s advisers issued misleading statements that indicated his clearance had been fully restored, when in fact he was still awaiting that status.

But he and his wife are still ramping up their profiles, ready again for a more public stage to pursue their projects after waiting out — and in some cases grinding down — their critics.

“I think they felt in some ways when things escalated that they thought it was best to keep a lower profile and hone in on their specific policy areas,” said Sarah Huckabee Sanders, the White House press secretary.

Ivanka Trump’s announcement this past week that she would shut down her fashion brand, based in New York, seemed to symbolise a recommitment to her life and her husband’s in Washington.

The woman who once said she did not intend to stay in the capital long enough to become one of its “political creatures” — people she feels are “so principled that they get nothing done,” according to someone familiar with her thinking — said on Tuesday that she did not know “if I will ever return to the business”.

“Any suggestion that they were going to leave the White House was just ridiculous,” said Treasury Secretary Steven Mnuchin, who was one of several allies the couple asked to speak on their behalf for this article. “They both have been dependable, valuable and effective partners for me and other members of the president’s Cabinet.”

Although they have kept a foothold in Manhattan, home is now in Washington, where their children attend Jewish schools and their house is routinely watched by paparazzi as they depart for work or go for a run. They live in a rented mansion in the Kalorama neighborhood, where they have courted groups of lawmakers and Washington hands in an effort to ease hyperpartisan tensions over cocktails and comfort food.

Jared Kushner and Ivanka Trump board Air Force One with their son, Joseph. Photo: Al Drago, New York Times

Their allies say this is a sign that the two, both children of businessmen, have adjusted to the market.

But intentionally or not, Kushner and Trump have redefined the expectations that people in their New York social circle once had that the two would be horrified by the president’s policies and change them.

“I never counted on it, but they themselves promoted the idea that they would save us,” said Hilary Rosen, a Democratic strategist who has been a vocal critic of the administration, before ticking off a list of policies Donald Trump has sought to dismantle.

As for separating immigrant families, she added, “How do they sleep at night?”

In response to critics like Ms Rosen, the couple have argued that they can temper Mr Trump only if he is willing to listen. And sometimes he has been: Ivanka Trump pushed for the expanded child tax credit in the tax cut bill that passed in 2017, and Mr Kushner has convinced the president that criminal justice reform is worthwhile, even as his attorney general remains a vocal opponent.

Mr Kushner appears to see himself as the custodian of Mr Trump’s political brand, offering his father-in-law “options”, and has spoken about clearing out the Republican Party of lingering resistance. He has privately said he has been taking action against “incompetence” and that any tensions are a result of fighting for his father-in-law’s best interests.

“I have greatly enjoyed working collaboratively with so many extraordinarily devoted and competent people,” Mr Kushner said through a spokesman a few hours before this article was published. “But those who have tried to undermine the president have found me to be an obstacle.”

His detractors say the friction stems from Mr Kushner’s meddling in things for which he is out of his depth, such as when the president, following his own preference, huddled with Mr Kushner and Ivanka Trump instead of his top policy advisers before his meeting with the North Korean leader, Kim Jong-un.

The couple’s allies insist that the expectations of their friends were way too high from the beginning, and that the admonitions to publicly denounce Donald Trump were never realistic or fair. They also say that the two have become more careful about how they engage with people, after early missteps.

Inside the White House, the couple’s influence is most felt in internal battles, particularly with aides they do not regard as loyal to their mission — or Donald Trump’s.

That is particularly true of Mr Kushner, who, critics say, shares his father-in-law’s desire for control. Over the course of Mr Trump’s campaign and presidency, Mr Kushner has been seen as trying to undercut or as being at odds with a long list of aides — some who remain, many who have left.

The list includes: Mr Trump’s first campaign manager, Corey Lewandowski; his first chief of staff, Reince Priebus, and his associates; his former chief strategist, Steve Bannon; Don McGahn, the White House counsel; White House counsellor Kellyanne Conway; the first head of the presidential transition, Chris Christie; former Secretary of State Rex Tillerson; Trump’s former personal lawyer, Michael Cohen; and his long-time lawyer Marc Kasowitz.

Their privileged permanence as family members has allowed them to outlast other aides in an environment where expectations have been shifted and, at times, lowered on their behalf.

Both husband and wife, like the president, are said to hang on to grudges, but Mr Kushner is far more transactional than his wife. Like his father-in-law, he appears to convince himself that fights did not happen if someone has become useful to him.