The 39-year-old father of five, who stayed in New York to run the family business with brother Eric when Trump took power, is in the eye of a gathering storm for meeting a Russian lawyer in a bid to get dirt on Hillary Clinton.
The real-estate scion and eldest presidential child has freely admitted to seeking dirt on his father's then rival for the presidency when he met Russian attorney Natalia Veselnitskaya in June 2016.
On Tuesday, he sought to get ahead of the backlash by releasing an email chain with the British music publicist and former tabloid journalist who set up the meeting "in order to be totally transparent."
Informed ahead of the meeting that material from the lawyer was part of an effort by Moscow to aid his father's presidential bid and incriminate Clinton, he emailed back in minutes: "If it's what you say I love it."
His response comes straight out of his father's combative playbook -- go on the offensive, flatly deny any wrongdoing and lash out at Democrats, the media and other critics in an attempt to brazen out the media maelstrom.
"Media & Dems are extremely invested in the Russia story. If this nonsense meeting is all they have after a yr, I understand the desperation!" he tweeted Tuesday to his 1.8 million followers.
On Monday, he called the initial revelations from The New York Times "a big yawn" and said he would be "happy" to "pass on what I know" in response to calls on the Senate Intelligence Committee to interview him.
'Much ado'
But taking another leaf out of his father's playbook, he quickly lawyered up -- engaging top-flight New York criminal defense attorney Alan Futerfas, whose past clients include alleged mob associates.
Futerfas's first move was to bat aside the backlash by quoting the title of a much-loved Shakespeare comedy to dismiss it as "much ado about nothing."
The first child of Trump's first marriage to Czech-born model and businesswoman Ivana, Don Jr was sent to boarding school after his parents mud-flinging divorce then his father's alma mater, the Wharton School of Finance.
He earned a reputation for partying hard, once getting arrested during Mardi Gras in New Orleans on charges of public drunkenness, before joining The Trump Organization in 2001 and rising to the status of executive vice president.
He has been a right-hand man of his father's for years in business. Since his father ran for president, Don Jr has cultivated a no-nonsense profile to resonate with Republican voters and is thought to harbor political ambitions of his own.
A public speaker, who can reportedly command tens of thousands of dollars, he also joined his father and sister Ivanka in gracing television screens on reality series "The Apprentice."
But while Ivanka and brother-in-law Jared Kushner followed Trump to Washington, Don Jr has ostensibly kept his distance to run the real-estate business in a deal that came under fire from ethics experts.
'Not curated'
But in the rocky first six months of his father's presidency, Don Jr has stuck his head above the parapet on several occasions, coming out swinging in his father's defense and proving his fierce loyalty time and again.
"I'm not a curated kind of guy," he admitted in a New York Times profile published in March. "I'm probably a little more like my father in that sense. You know, I say what I'm thinking."
Ronald Kessler, author, former investigative reporter and friend of the president, agrees. "Just like his father, he is very candid," he told AFP.
It is an approach that plays well to the Trump base.
"If you believe that all of this is nonsense, then you admire Don Jr for being very forthright... and saying it like it is," adds Kessler.
But if even friends admit the meeting with Veselnitskaya was "amateurish," neither is it the first time that Don Jr has landed in hot water.
Despite a well-received speech at the Republican National Convention last year, there were times during his father's campaign, when he sparked controversy, such as comparing Syrian refugees to a bowl of potentially deadly Skittles candy.
A member of the National Rifle Association, he has come under fire for hunting in Zimbabwe. As a child, he spent part of his summers hunting and fishing with his grandfather in then Czechoslovakia.
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