Few of Donald Trump’s genuinely populist economic proposals from the campaign trail seem to have survived the transition to the White House. In retrospect, it seems foolish to have put any stock whatsoever in his sundry musings about “the government” paying for everyone’s health care, or hedge funds “getting away with murder,” or how the wealthy should “pay more” in taxes, or how he’d like to see a minimum wage “increase of some magnitude.” Each of those proposals was quickly replaced by its opposite, almost as if Trump doesn’t care about the words he says or actually believe in anything at all.

So it should come as no surprise that Donald Trump has vacillated on the possibility of bringing back Glass-Steagall, the Depression-era law that separated commercial and investment banks until 1999 and the repeal of which some people blame for the financial crisis. “I’m looking at that right now,“ Trump told Bloomberg earlier this month. “There’s some people that want to go back to the old system, right? So we’re going to look at that.”

Historically, a sitting president mulling the possibility of breaking up the big banks would have sent shivers down the spines of Wall Street C.E.O.s, with a market reaction to match. Instead, investors barely blinked. Because, by their own admission, no one on Wall Street really takes Trump seriously anymore. At this point, they’re fully aware of the fact that by a quirk of biology, the president’s brain is not connected to his mouth and so the words just tumble out at will. “I don't take Trump seriously,” a senior executive with “one of the country’s six largest banks” told Reuters earlier this month. “I’m listening less and less.” “Break up the banks? That ain’t going to happen,” Citigroup adviser Rick Hohlt told Bloomberg.

The pronouncements of other Trump minions appear similarly worthless. Lately, some administration officials have taken to using the term “21st-century Glass-Steagall”—a term they claim does not actually involve breaking up banks, which is kind of like when Ivanka Trump said she was “complicit,” if complicit meant “wanting to be a force for good and to make a positive impact.”

Senator Elizabeth Warren is a very smart woman who, like Wall Street, is presumably wise to the fact that one cannot take Trump and Co. literally or seriously. But bringing back Glass-Steagall is something she’s advocated for years, having introduced just such a proposal in 2015. So when Treasury Secretary Steven Mnuchin showed up to testify before the Senate Banking Committee on Thursday, she decided to take the opportunity to force him to admit that when Donald Trump says he’s “looking into” breaking up the banks, he’s actually full of it. The result was an absolutely surreal exchange that must be read in full:

Elizabeth Warren: You said we need a 21st-century Glass-Steagall at your confirmation hearing. And now you’ve just said the opposite. In the past few months, you and the president have had a number of meetings with big-bank C.E.O.s and lobbyists—is that the reason for the reversal on Glass-Stegall?

Steven Mnuchin: Not at all; there actually wasn’t a reversal.

Warren: There wasn’t a reversal?

Mnuchin: Let me explain.

Warren: I’m ready.

Mnuchin: The Republican platform did have Glass-Stegall. . . . The president said we do support a 21st-century Glass-Steagall, that means there are aspects of it that we think may make sense. But we never said before we support a full separation of banks and investment banking.