On a Wall Street conference call in April, Eric Trump made a pitch for the newest venture in his family’s rapidly expanding cryptocurrency empire.

Mr. Trump, the president’s second son, said he was joining forces with the crypto firm Hut 8 to start a company focused on Bitcoin mining, the business of running energy-guzzling machines to generate new coins.

Bitcoin mining is a notoriously difficult industry. But in the pitch, Mr. Trump made clear that the policies of his father’s administration would give the new company, American Bitcoin, a “competitive advantage.”

“We’re doing it in America with a government that’s dedicated to low-cost energy,” he said, later adding, “We’ve got the best energy policy in this country. That policy is only getting better.”

Virtually every aspect of the Trump family’s business portfolio is fraught with conflicts of interest that have blurred the boundary between government and industry. The debut of American Bitcoin, which is set to merge with a publicly traded company later this year, has heightened those concerns, introducing new ethical questions and pulling the Trumps even deeper into crypto, a business the White House has aggressively championed.

President Trump is already financially intertwined with two other crypto ventures — a so-called meme coin created by a longtime business partner, and a separate company, World Liberty Financial, that he and his sons founded before the election. At the same time, he has ended a yearslong enforcement campaign against crypto companies by the Securities and Exchange Commission and vowed to sign legislation that would advance the industry’s priorities.