Indeed, Sen. Warren has been a vocal critic of many aspects of Powell’s leadership, from his monetary policy stances to his handling of regulatory rollbacks. She publicly said she didn’t believe Powell should be the man to lead the Fed.

However, the Democrat said Powell’s power to make such decisions independently of political pressure is one of the core strengths of the American economy. Threatening it—or being perceived to threaten it—will only hurt voters and the markets in the long run.

Yet that is precisely the cause of the volatility injected into markets this week—and not for the first time.

Investors reacted shakily to this week’s news that Trump had spoken to lawmakers about how legitimately he could move Chair Powell aside, an unprecedented intervention into the federally mandated independent central bank. President Trump then somewhat walked back the threat, saying it was “highly unlikely” (though not impossible) that he would fire Powell.

Sen. Warren told Fortune in an exclusive interview: “I often disagree with the Fed chair on both monetary policy and bank supervision, but I don’t try to cook up a pretext to get him fired.

“I recognize that ultimately any of us can try to persuade the Fed chair about the best direction to go for the economy, but the Fed is independent and over time, over the long haul, our markets and our nation benefit from that independence.”

However, White House spokesman Kush Desai countered to Fortune: “President Trump can both call out the Fed for failing to do its job by its own stated objectives and ensure that taxpayer money is not wasted on things that do not benefit the American people.”

Since winning the Oval Office, President Trump has aggressively lobbied Powell for rate cuts, and a loosening of monetary policy is now a move that many economists agree is the correct course.

However, they may disagree with the White House’s methods, which have included everything from threatening to fire Powell to questioning his management of the Fed on aspects including the bank’s office renovations.

Indeed, President Trump’s actions are now going far enough to make Republican senators uneasy—as GOP North Carolina Sen. Thom Tillis said in a floor speech this week: “If anybody thinks it would be a good idea for the Fed to become another agency in the government subject to the president, they’re making a huge mistake.”

Trump is ignoring lessons from the past

Previous administrations learned the hard way what it means to meddle in the Fed.

Considered by many to be the worst leader in the Fed’s history, president Arthur Burns oversaw a period of stagflation (high inflation and low growth) in the 1970s in part because, historians say, he was too weak to stand up to President Nixon in the White House. 

Speaking exclusively to Fortune earlier this week, JPMorgan’s Jake Manoukian used the Burns/Nixon example to illustrate how political intervention had only proved the point for Fed autonomy, saying: “What happened is the Fed evolved after that to become a much more independent institution that wasn’t as beholden to the White House.

“Even the way that the board is structured and the way that the governor’s terms are out of sync with the political cycle and, the fact it still has a chair but a board where every vote counts.”

The next nominee needs ‘the brains and the guts to stand up and do what the economy demands’

Warren also voiced concerns that President Trump’s interference in the Fed may outlast Chair Powell, whose term expires in 2026, at which point the Oval Office will be able to nominate the next leader of the central bank.

Trump has already said he won’t nominate a chairman or woman who isn’t willing to cut the base rate—but concerns at the more extreme end of the spectrum are that the incoming Fed boss will be something of a puppet for the White House.

“Virtually every Trump appointee come[s] before Congress and pledged their loyalty to Donald Trump,” Sen. Warren, formerly the chair of the subcommittee on economic policy, added.

“While many people may roll their eyeballs at that, we also recognize that the president has the power to fire members of his cabinet. 

“They serve at his pleasure and … it may not be the smartest way to build a cabinet, but it’s at least within the range of what is a president’s reasonable power—to pick the people generally that he wants to work with. The Fed chair is different, the whole point of the Fed is independence.”

This presents a delicate balancing act for the potential nominee: Maintaining Trump’s support throughout the process while convincing Congress and the markets that the Fed will truly act in the long term in the best interests of the economy.

“The … chair nominee is going to have a hard time threading the needle between obsequiousness to Donald Trump and convincing the markets that that nominee has the brains and the guts to stand up and do what the economy demands rather than what Donald Trump demands,” Sen. Warren added.