Elon Musk is the world's richest man, owns one of its biggest communications platforms and is increasingly politically active. Washington is seeing for the first time just how potent a blend that is.
An ally so close to President-elect Donald Trump that he's informally spoken of as the "first buddy," Musk was instrumental in derailing a bipartisan stopgap government funding bill, deriding it as chock full of "pork" after lawmakers added on aid for disaster victims and farmers beyond simply delaying a government shutdown.
Now, the man who is reportedly worth over $450 billion, is establishing himself as a Washington power player -- the likes of which there is little historical precedent.
"I do think that there are multiple examples, but Elon Musk is bigger than all the previous business leaders in government put together," said one source close to Trump's transition.
"You have what I consider to be an intersection of three different arcs: a man of wealth, a man with the largest and most efficient communication system in the world combined with someone who cares about one of the biggest issues Americans care about," the person added, referencing the amount of government spending.
Republicans and Democrats on Capitol Hill appeared earlier this week to be on a glide path to passing a funding bill that would prevent a shutdown that would be triggered early Saturday morning. Some Republicans were grumbling about the size of the bill and the add-ons for disaster recovery and farmers, without accompanying offsets, but the legislation as anticipated to pass both chambers of Congress with anticipated support from Democrats.
MORE: House Republicans say they have a spending deal, but not that Trump's on boardThen, Musk chimed in.
"Any member of the House or Senate who votes for this outrageous spending bill deserves to be voted out in 2 years!" Musk wrote on his social media platform X.
"Please call your elected representatives right away to tell them how you feel! They are trying to get this passed today while no one is paying attention," he added in a second post to his more than 200 million followers.
Before long, the defections began.
House Republican after House Republican announced they'd oppose the bill. Trump himself ultimately weighed in, pushing for a clean stopgap bill that also eliminated the debt ceiling -- the limit the government is allowed to borrow, which is set to be hit under his term but is also a third rail in U.S. politics that could pose severe risk of preventing a funding bill's passage.
The criticism grew loud enough for Speaker Mike Johnson, R-La., and other House leaders to go back to the drawing board, scrambling to figure out language that would pass muster with Trump, Musk and House Republicans in time to keep the lights on.
But the risk to House Republicans, from its leaders to the lowliest backbencher, was made clear.
"If the speaker acts decisively, and tough, and gets rid of all of the traps being set by the Democrats, which will economically and, in other ways, destroy our country, he will easily remain speaker," Trump told Fox News Digital, a departure from his more recent statements offering firmer support for Johnson as he seeks the gavel in the next Congress.
And Trump will not be alone in those kinds of threats, it appears.
One source familiar with Senate leadership's thinking sounded a skeptical note about how much Musk would be able to bend the Senate to his will but conceded that he had significant influence with the president-elect and House Republicans, whose biannual reelection efforts make them more vulnerable to the consequences of crossing Trump.
"He definitely has sway and definitely has the ability to be heard," the source said.
House Republicans, for their part, appear to have no problem with that.
MORE: Trump says he gave permission to Elon Musk to trash GOP-proposed spending bill on XAlready, some lawmakers are flirting with the far-fetched idea of making Musk the House speaker over Johnson. And, spending hawks said, if a slimmed down funding bill is the result of Musk's intervention, the more the merrier.
"Elon Musk is going to cause problems for Congress, but they're good. It's really, really good. I appreciate it because he's going to expose the waste, fraud, abuse you've seen in Congress for decades," said Rep. Troy Nehls, R-Texas.
Fans like Nehls are likely to get their wish. Musk is being tapped to co-lead the "Department of Government Efficiency," the private task force designated by Trump with cutting supposedly wasteful spending.
Democrats, for their part, are livid over Musk's early flex, accusing Republicans of being pawns to an oligarch.
"Mr. Musk has kind of set himself up as the preemptor of policy here because he has no accountability. And so, God bless him, he's entitled to his opinion, and looks like he's going to be exercising that throughout the Trump term," said Rep. John Larson, D-Conn.
"Democrats and Republicans spent months negotiating a bipartisan agreement to fund our government," Sen. Bernie Sanders, I-Vt., added on X. "The richest man on Earth, President Elon Musk, doesn’t like it. Will Republicans kiss the ring? Billionaires must not be allowed to run our government."
Still, as a wealthy, unelected appointee, he has fewer guardrails than other power players in Washington -- and as long as his appetite for political knife fighting lasts, so, too, could his influence over Washington's levers of power.
"He is relatively out of reach [of his critics] because of his wealth," the source close to Trump's transition said. "The idea that someone with that kind of resilience is doing this, I think we're going to see profound change."