Musk made direct appeals to Trump to reverse sweeping new tariffs.

The world’s richest person, a key Trump adviser and political donor, was ultimately unsuccessful.

Over the weekend, as Elon Musk launched into a barrage of social media posts criticizing one of the lead White House advisers for President Donald Trump’s aggressive tariff plan, Musk was going over that same official’s head — and making personal appeals to Trump.

The attempted intervention, confirmed by two people familiar with the matter who spoke on the condition of anonymity to discuss private talks, has not brought success so far; Trump threatened Monday to add new 50 percent tariffs on imports from China to go along with the 34 percent taxes he announced last week. (The president did signal he was open to negotiations on some aspects of his policy.) Musk, meanwhile, posted a video to X in which the late conservative economist Milton Friedman touted the benefits of international trade cooperation — “the impersonal operation of prices,” as he put it — breaking down the sources of the materials that go into a simple wooden pencil.

Musk’s break with Trump over a signature administration priority marks the highest-profile disagreement between the president and one of his key advisers, who poured nearly $290 million into backing him and other Republicans in last year’s elections and has been leading the U.S. DOGE Service’s cost-cutting efforts since January. Musk has also disagreed with other members of Trump’s coalition on issues such as H1-B visas for skilled immigrants and on DOGE’s approach to government spending.

On Saturday, Musk took aim at the administration official who has been key to developing the tariff plans, White House trade adviser Peter Navarro, lighting into his credentials.

“A PhD in Econ from Harvard is a bad thing, not a good thing,” Musk wrote.

On Tuesday morning, Musk again targeted Navarro in a series of X posts, as he responded to comments made by Navarro on CNBC calling Musk a “car assembler,” rather than a manufacturer “in many cases.”

“Navarro is truly a moron,” Musk said in one post decrying the claim as false, before calling him “dumber than a sack of bricks” in another, and following up by defending Tesla, saying it is “the most vertically integrated auto manufacturer in America with the highest percentage of US content.”

Musk concluded by saying, “Navarro should ask the fake expert he invented, Ron Vara,” a reference to Navarro’s reported use of a fictional trade expert — an anagram of his last name — in his books.

Navarro did not respond to a request for comment Monday, nor did he immediately respond to a follow-up Tuesday.

“Look, these are obviously two individuals who have very different views on trade and on tariffs,” White House press secretary Karoline Leavitt told reporters on Tuesday. “Boys will be boys and we will let their public sparring continue. And you guys should all be very grateful that we have the most transparent administration in history. And I think it also speaks to the president’s willingness to hear from all sides.”

In an interview with Italian Deputy Prime Minister Matteo Salvini over the weekend, Musk also said he would like to see a “free trade zone” between Europe and the United States: “At the end of the day, I hope it’s agreed that both Europe and the United States should move ideally, in my view, to a zero-tariff situation.”

Musk also said that he would like more freedom for people to move between countries in Europe and the United States and work in either “if they wish.”

“That has certainly been my advice to the president,” he said.

Musk, who is chief executive of electric vehicle maker Tesla, has long seen tariffs as detrimental to the business aims of a company that counts both the United States and China as key manufacturing and consumer hubs. Other car manufacturers, though, are likely to be hurt more by the new tariffs, analysts have said.

But Musk has opposed tariffs since at least Trump’s first term, when Tesla filed a lawsuit seeking to overturn the tax on Tesla’s imports from China to the United States.

In 2020, top executives at Tesla wanted the company to sue the Trump administration over its tariffs on China. Musk initially agreed, saying that parts of Trump’s package were unfair to the carmaker. But after Tesla filed the lawsuit in September 2020, Musk reacted in a “super negative way” about the decision, even berating some staff members for suggesting Tesla file the suit, according to a person familiar with the matter, because right-wing accounts on Twitter said Musk was trying to curry favor with the Chinese and was going against Trump’s “America First” agenda.

Many of the business and technology leaders who supported Trump’s candidacy were stunned by the president’s decision to go forward with such steep tariffs, and equally disappointed that they weren’t able to exert more influence on the policy, the two people familiar with the matter said. People in Musk’s orbit made direct appeals to friends in the Trump administration, including Vice President JD Vance and Musk, arguing for what they felt were more sensible free trade policies. One Musk friend, investor Joe Lonsdale, posted on X that he had argued to “friends in the administration” in recent days that tariffs would hurt American companies more than Chinese ones. Lonsdale declined to comment about his arguments beyond his X post.

A group of business leaders worked over the weekend to put together an informal group that would lobby members of the Trump administration for more moderate policies, said one of the people.

Many supported Trump last year even while knowing that the steep tariffs he had long promised could be destructive to both the tech industry and the economy as a whole, but they felt that Trump could be swayed by advisers such as Treasury Secretary Scott Bessent to adopt a softer approach, the people said. The business leaders also did not anticipate that Commerce Secretary Howard Lutnick, who had been one of Musk’s key conduits into Trump’s orbit, would be such a strong advocate of protectionist policies.

The dispute between the president and one of his most influential advisers comes just weeks before Musk, the world’s richest person, is expected to depart his post in the administration. It also comes amid increasing pressure on Tesla to reverse signs of slumping demand — prompted in part by Musk’s foray into politics.

“The backlash from Trump tariff policies in China and Musk’s association will be hard to understate,” said Dan Ives, analyst with Wedbush Securities, an enthusiastic Tesla backer who lowered Tesla’s stock price target — a measure of its viability — from $550 to $315 “to reflect these new softer demand estimates.”

“Tesla has essentially become a political symbol globally … and that is a very bad thing for the future of this disruptive tech stalwart and the brand crisis tornado that has now turned into an F5 tornado,” he wrote.