In late June, Donald Trump arrived at a factory in Monessen, Pennsylvania, and stood before a wall of crushed cans to discuss one of his favorite topics: trade. The setting befit the oration. This particular factory, after all, had once employed hundreds of aluminum workers; these days, however, it relied on about 35, who largely prepare the metal for recycling. Standing beside his Great Wall of Cans, Trump bashed NATO and globalization, among other organizations and inexorable forces, before honing in on his quixotic plan to single-handedly revive Monessen’s fortunes. Trump would simply utilize his experience in the real-estate business to turn around the moribund American steel industry. The return of the steel business, he promised, would send a new generation of skyscrapers “soaring, soaring” into the sky.

Trump, who has often been flanked at larger campaign rallies by his wife and extended family, was alone. And rather than speaking extemporaneously, as is his custom, he was reading prepared remarks from a teleprompter. The initial draft of his speech, rather notably, had only one word in its file name: Jared, seemingly a reference to Jared Kushner, the presumptive nominee’s increasingly influential son-in-law, who reportedly had lent a hand in writing this speech.

Kushner, through a publicist, declined to comment on the incident, and for this story. But the 35-year-old real-estate scion has recently emerged, alongside his wife, Ivanka Trump, as one of Trump’s key advisers. Earlier this week, The New York Times called him a de facto campaign manager, a position he assumed after he, along with Ivanka, reportedly urged the ouster of Trump’s impetuous manager Corey Lewandowski. And it was Kushner, according to someone with direct knowledge of the conversation, who was on the phone with Rupert Murdoch and Fox News C.E.O. Roger Ailes “down to the wire” in the days preceding the controversial Fox News debate, in January, attempting to broker a peace deal between his father-in-law and the network. (In the end, his efforts were unsuccessful and Trump skipped the debate.)

In March, Senator Jeff Sessions credited Kushner with arranging a discussion between Trump and Republican lawmakers. Kushner, with the assistance of New York Observer editor Ken Kurson, according to Reuters, also crafted Trump’s well-received speech to AIPAC, one of his early experiments with a teleprompter. “Trump is in the process of making a new Republican Party, and Jared will be part of it,” Myers Mermel, a fellow real-estate executive told me. “And it’ll be a much different Republican Party than we had in the past.”

On some level, the specter of Kushner campaigning beside his infamous father-in-law seems rather improbable. Outside of their involvement in the real-estate business, Kushner and Trump appear to be opposites. Trump has run a campaign based, in part, on racial undertones; Kushner, on the other hand, is an observant Jew. Trump is the Republican Party’s presumptive nominee for president; Kushner comes from a well-known Democratic family (in fact, his own father’s former tormentor in New Jersey, Chris Christie, is now essentially his father-in-law’s right hand).

Furthermore, Trump’s style could be characterized as a steroidal version of Las Vegas, as designed by Uday Hussein. Contrastingly, visitors to Kushner’s office on the top floor of 666 Fifth Avenue, which his family purchased for $1.8 billion in 2007, pass under a Noguchi-designed wave-like ceiling in the building’s lobby. Kushner’s floor is serene, and features a bubbling fountain. He and Ivanka Trump are the epitome of well-bred understatement. Their apartment, recently profiled in Elle Décor, features Christian Liaigre upholstery and midcentury chic. “Besides being devastatingly handsome, he is well mannered, well bred, and so well turned out,” notes the inimitable Peggy Siegal, who has organized several events for The New York Observer, which Kushner purchased a decade ago for what was reported to be nearly $10 million.