Salwan Georges/Detroit Free Press/TNS via Getty Images Weeks after he said he'd reinstate the Glass-Steagall Act, Donald Trump now wants to halt all new financial regulations.

WASHINGTON ― Back on July 18, Donald Trump’s campaign announced that it was backing a major Wall Street overhaul. Reinstating the Glass-Steagall Act, a priority of Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.), would be an official plank of the Republican Party platform.

And then on Monday, Trump called to halt all new financial regulations. As Trump policy reversals go, this one was a slow burn, with Trump savoring three full weeks of consistency before deciding he’s okay with establishment Republican orthodoxy after all. Usually, the flip-flop is faster: One day, Trump says “our wages are too high.” A day or two later, he insists he’s never said such a thing.

Reinstating Glass-Steagall would be a major reform. It would require the largest banks to break up into smaller, safer institutions, and bar banks that do the boring business of extending loans and accepting deposits from playing in the riskier world of securities trading. This separation between deposit-taking and securities trading would cut off risky activity from cheap, federally subsidized funding.

But Trump’s ban on new banking rules wouldn’t just undercut his own Glass-Steagall proposal. It would also derail many of the smaller-bore reforms included in the 2010 Dodd-Frank financial reform law. One of those still-unfinished rules is designed specifically to prevent some ugly activity that a member of Trump’s economic advisory team instigated during the lead-up to the 2008 crash.

Most of Trump’s economic team consists of major Republican donors from the finance and real estate worlds. The biggest of the bigwigs, however, is billionaire hedge fund manager John Paulson.

Paulson initiated the infamous Goldman Sachs “ABACUS” trade, which ultimately resulted in Goldman Sachs settling securities fraud charges with the Securities and Exchange Commission for $550 million. Paulson went to Goldman Sachs asking the firm to create a new security linked to particularly bad mortgages that he expected to default. Paulson could bet against it, and when the mortgages blew up, he would make money. Goldman Sachs did it, and sold the security to its clients as an investment in the housing market.

But Goldman Sachs also joined Paulson in betting against the new security. As a result, the firm was betting against its own clients and, according to the SEC allegations, deceiving them by failing to note that the security was created by people who expected it to fail, including Goldman Sachs itself.

The case relied on disclosures ― the SEC argued that Goldman Sachs had committed fraud not because the trade constituted a massive conflict of interest, but rather because Goldman Sachs had not disclosed important information about the trade to investors.

As ProPublica detailed in April, an SEC attorney wanted the agency to go after not only Goldman Sachs, but its managers and even Paulson himself.

“Each of them knowingly participated, as did Goldman and Tourre, in a scheme to sell a product which, in blunt but accurate terms, was designed to fail,” SEC attorney James Kidney wrote in a 2009 memo obtained by ProPublica. “The current pre-discovery evidence suggests they should be sued for securities fraud because they are liable for securities fraud.”

Paulson was not immediately available to comment, but told ProPublica that the hedge fund never mislead anyone on the deal.

Ultimately, the SEC only pursued the lowest-ranking Goldmanite involved in the deal, Fabrice Tourre, who was fined about $825,000 in 2014. The SEC has faced plenty of criticism for being soft on Wall Street. But the agency and other regulators have protested that fraud cases are hard to win, and they want to be careful with limited resources.

Dodd-Frank tried to make the SEC’s job easier. Section 621 of the law simply banned trades like the Paulson-Goldman deal. If there’s a conflict of interest, you can’t do it. Regulators wouldn’t have to prove that a failure to disclose the conflict was fraudulent. Congress ordered the SEC to finalize a new regulation fulfilling this vision within 270 days of the law’s passage.

But the SEC never did. Dodd-Frank passed over six years ago, and while the agency unveiled a proposal in 2011, it never acted on it. In April, eight senators, led by Sen. Dianne Feinstein (D-Calif.), sent a letter to SEC Chair Mary Jo White urging her to finalize the rule. White has yet to take action.

If Trump has his way, she’ll never have to.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims ― 1.6 billion members of an entire religion ― from entering the U.S.