With markets nosediving across the globe, President Trump played golf, raised money for MAGA and dug in deep on his tariff plans, after warning Americans to buckle up, Jim VandeHei and Mike Allen write in a "Behind the Curtain" column.

• "THIS IS AN ECONOMIC REVOLUTION, AND WE WILL WIN," he said on Truth Social on Saturday. "HANG TOUGH, it won't be easy, but the end result will be historic."

Why it matters: For one of the first times in his career, Trump seems more bent on making a point than making a deal. He's confident nations will bend to his will, just as universities and law firms have.

• "We don't have a playbook for fully committed Trump," a longtime adviser tells us. "He's always been the ultimate pragmatist — everything was on the table at all times: 'Give me a win and I'll consider anything.'"

CNBC now: "GLOBAL MARKET MELTDOWN INTENSIFIES."

• Trump told reporters aboard Air Force One yesterday: "I don't want anything to go down. But sometimes you have to take medicine to fix something."

Behind the scenes: Trump officials say 50+ countries have approached the administration to make tariff deals. But people involved in the process say there's frustratingly little structure or coordination around the negotiations.

• A White House official told us: "The phone lines are open and nations are free to make their pitch on how they will correct for decades of taking advantage of the American consumer. But for businesses looking for certainty, the message is clear: Don't wait, come build in America."

💡 Reality check: There were safe, easy and still fast ways to do all the things Trump is doing, many Republican insiders tell us.

• Trump could have laid out specific tariff threats for each country, given them a short period to comply with a proposed compromise on great U.S. terms, and explained his thinking before spooking the markets.
• Trump could have spent an extra month targeting spending cuts with precision — so he didn't have to cut and then rehire people deemed more vital than first thought.
• And he could have set up a more thorough vetting program for deportation — so his broadly popular action didn't get undermined by locking up or sending off people who are not clear-cut violent criminals.

📱 Between the lines: We talked to a bunch of leaders of businesses of all sizes this weekend. All are scrambling — even panicked — after all their planning was upended. But Trump and his Cabinet showed a real disconnection from the economic chaos unfolding coast to coast.

• On Friday, Trump headlined a $1 million-a-plate dinner fundraising dinner at Mar-a-Lago for MAGA Inc., the top pro-Trump super PAC.
• Then Trump golfed near Mar-a-Lago on Saturday and Sunday — and yesterday posted a video of himself teeing off.
• The White House issued a statement Saturday saying: "The President won his second round matchup of the Senior Club Championship today in Jupiter, FL, and advances to the Championship Round."

📺 Commerce Secretary Howard Lutnick said on CBS' "Face the Nation": "The army of millions and millions of human beings screwing in ... little screws to make iPhones, that kind of thing is going to come to America."

• "It's going to be automated," Lutnick continued. "And great Americans, the tradecraft of America, is going to fix them, is going to work on them. They're going to be mechanics. There's going to be HVAC specialists. There's going to be electricians."

That's amid warnings that Trump's tariffs could raise the cost of an iPhone by 30% to 40%. As Reuters put it: "A $2,300 Apple iPhone? Trump tariffs could make that happen."

"Economic nuclear winter": Bill Ackman, an investor who has been among the most powerful pro-Trump voices on X, pleaded yesterday in a post with 9 million views: "May cooler heads prevail." Otherwise, he said, "we are heading for a self-induced, economic nuclear winter, and we should start hunkering down.

• Ackman wants Trump to call a 90-day timeout, "negotiate and resolve unfair asymmetric tariff deals, and induce trillions of dollars of new investment in our country."

"The country is 100% behind the president on fixing a global system of tariffs that has disadvantaged the country," Ackman wrote. "But, business is a confidence game and confidence depends on trust.

• "[B]y placing massive and disproportionate tariffs on our friends and our enemies alike and thereby launching a global economic war against the whole world at once," Ackman continued, "we are in the process of destroying confidence in our country as a trading partner, as a place to do business, and as a market to invest capital."

The bottom line: Cracks in the Trump coalition are showing, however slightly. Even Elon Musk slammed protectionist Trump adviser Peter Navarro, and tweeted cryptic but clearly pro-free-trade clips.

When sky-high inflation pummeled Americans in 2022, the labor market was booming and wages were rising, softening the blow. Now we're in a more vulnerable place, Axios' Emily Peck writes.

• Why it matters: Economists fear that if tariffs drive inflation, wages won't keep up — leading to lower incomes and real pain.

🧮 By the numbers: Wage growth cooled to 3.8% in March from 4% the previous month. It's been declining since the fall.

• The labor market is in a solid place, but there are worrying signs. Hiring is well off the heights of 2022. A white-collar hiring recession is in play. And now a glut of highly educated ex-federal employees is set to hit that market.

🧠 Reality check: We're in totally uncharted waters. The average effective tariff rate would rise to 22.5% if all announced policy changes stick — the highest since 1909, The Budget Lab at Yale found.

• It's possible that higher prices and unemployment (or fear of it) will push spending down and keep inflation in check.

🔌 "Which system is gonna be hurt the most when you jab a fork into a light socket? I don't really know," says Michael Madowitz, principal economist at the Roosevelt Institute. "That's why we don't force forks into light sockets, traditionally."

• Get Axios Markets.

JPMorgan Chase CEO Jamie Dimon says in his annual letter, out this morning, that the U.S. economy was already weakening before President Trump's sweeping new tariffs — and those levies will now fuel inflation and slow growth.

• Why it matters: Dimon, for decades one of the most powerful figures in global finance, is offering his closely watched views in the midst of a global market crisis, writes Axios' Ben Berkowitz, managing editor for business.

"There are many uncertainties surrounding the new tariff policy: the potential retaliatory actions, including on services, by other countries, the effect on confidence, the impact on investments and capital flows, the effect on corporate profits and the possible effect on the U.S. dollar," Dimon writes in his 58-page letter.

• "The quicker this issue is resolved, the better ... [S]ome of the negative effects increase cumulatively over time and would be hard to reverse. In the short run, I see this as one large additional straw on the camel's back."

Between the lines: In his 2024 letter, Dimon laid out a pro-trade message. This year, he acknowledges the U.S. is right to protest, and try to fix, some trade abuses.

• But he also says the answer is negotiations, particularly those that preserve international economic alliances.

Read his full letter.

Data centers, a physical manifestation of the AI race, are spreading across the country, with plans for massive additional investment and construction.

• Why it matters: Innovation infrastructure, once concentrated in coastal bubbles, is sprouting nationwide.

The world's densest data center hub, Data Center Alley, is in Northern Virginia.

• 40% of U.S. data center employees are in five states: California, Texas, Florida, New York and Georgia, the U.S. Census Bureau says.

Jim & Mike's Axios AM Executive Briefing has a subscriber-only special report coming on the collision of AI and Washington.

• Why it matters: AI is one of the biggest forces driving the simultaneous reordering of governance, media, business and global geopolitics.

Sooner than most realize, Ph.D.-level super-agents will be at our service, disrupting habits of life and work.

• Our special report — written with the insights and intel of our Axios Pro: Tech Policy experts — includes how D.C. thinks about AI ... D.C. power players on AI ... and specific bills and regulations to watch. Plus we'll take you inside the Trump administration's AI Action Plan.

On April 16, we'll host an online conversation about tech regulatory changes, mergers and growth.

• Subscribe here.

HHS Robert F. Kennedy Jr. tweeted yesterday after visiting the epicenter of West Texas' growing measles outbreak — the same day a funeral was held for a second child who wasn't vaccinated and died from a measles-related illness:

"The most effective way to prevent the spread of measles is the MMR vaccine."

Why it matters: It was Kennedy's most direct statement on the issue. He has avoided endorsing the vaccine, and stopped short of saying he "recommended" it, "as public health officials have called on him to do," STAT reports.

• Less than six hours later, STAT notes, Kennedy promoted unorthodox, unproven measles treatments in another post.

Get the latest: The U.S. has more than double the number of measles cases it saw in all of 2024, with Texas reporting another large jump in cases and hospitalizations on Friday.

The AI chatbots we invited into our long-running Axios AI+ women's bracket challenge this year were no match for most of the competitors among Axios readers and staff, chief tech correspondent Ina Fried reports.

• Not only did the AI chatbots have trouble filling out their March Madness brackets, they ended up finishing below most of the human pickers, at least for the women's tournament, which wrapped up yesterday.

Why it matters: AI bots are likely to become key helpers in every realm of human activity — fantasy sports included. But all that computing power doesn't guarantee perfection.

• Keep reading.

Alex Ovechkin fired just about the perfect shot from the place on the ice that has defined his remarkable career. When the puck hit the net, it made him the top goal scorer in NHL history, AP reports.

• Ovechkin broke Wayne Gretzky's record by scoring his 895th career goal yesterday as his Washington Capitals battled the New York Islanders.

Ovechkin took a cross-ice pass from longtime teammate Tom Wilson and fired a laser, rewriting a record many thought would never be broken.

With the excitement of a child, the 39-year-old Russian superstar belly-flopped onto the ice as tens of thousands of fans around him cheered and chanted: "OVI! OVI!" Teammates streamed off the bench, mobbing him in celebration.

• The ultimate footnote: Islanders beat Caps, 4-1.

1-min. video: "Ovechkin fires! SCOOOORE! The chasing days are done!"

• Ovi speaks ... How it happened.