The top Democrat on the U.S. House Financial Services Committee demanded the chairman of the Securities and Exchange Commission explain during a Wednesday hearing what happened with the agency's enforcement interest in Tron Foundation founder Justin Sun and whether his ties to President Donald Trump have had an influence.

Representative Maxine Waters highlighted the U.S. securities regulators' abandonment of almost all of its previous crypto enforcement cases when Trump took over the White House and replaced the agency's leadership last year. She underlined the case against Sun in which the agency investigated Sun and his company on wide-ranging allegations, including that they'd improperly jacked up the price of their token (TRX).

SEC Chairman Paul Atkins told the committee that he couldn't discuss individual cases, but he expressed his willingness to have further conversations in a confidential briefing "to the extent the rules allow me to do that."

Sun was formally accused by the SEC in 2023 of trying to artificially inflate TRX's trading volume through a so-called "wash trading" scheme, allegedly having his own employees "engage in more than 600,000 wash trades of TRX between two crypto asset trading platform accounts he controlled." But the agency moved to pause that case in court a year ago "while they consider a potential resolution." No resolution has yet been announced.

"Well, while you were exploring a potential resolution, Mr. Sun has been busy ingratiating himself within Trump's orbit," Waters said to Atkins, referencing Sun's ties to the Trump family's World Liberty Financial Inc.

Waters also flagged a more recent development in which an alleged former girlfriend of Sun suggested publicly that she had evidence of TRX manipulation.

Spokespeople for Tron and Sun didn't immediately respond to a request for comment on the exchange during Wednesday's hearing.

"Chairman Atkins, you have said that under your leadership, the SEC will focus on real fraud," she said. "Does your statement extend to fraud in the crypto market?"

"Whatever involves securities," Atkins responded.

His agency last year dropped high-profile enforcement matters against Binance, Ripple, Coinbase, Kraken, Robinhood and several other companies, with its new management criticizing the "regulation-by-enforcement" approach to crypto under the agency's previous leadership.

Asked by another Democratic lawmaker whether his agency ever protects investors at a cost to Trump's businesses, Atkins responded, "As far as what the Trump family does or not, I can't speak to that."

While Democrats have focused on the SEC's reversal of its previous crypto enforcement work, Republicans on the committee concentrated on Atkins' promises that he'll provide the crypto industry regulations to clarify — alongside the Commodity Futures Trading Commission — how the companies can operate in the U.S.

Atkins said the agencies are working on rules "consistent with what's in the Clarity Act that you all passed here in the House, and hopefully what will come out of the joint work that you're doing with the Senate. So, you know, we will carry that forward, and basically it'll help give certainty as to where the jurisdiction of the two agencies are."

As the SEC and CFTC work on that joint effort under their Project Crypto label, the CFTC also recently moved to embrace the new U.S. stablecoin approach by revising an earlier so-called "no action" letter that now clarifies that national trust banks can issue payment stablecoins, expanding the list of eligible tokenized collateral to include the tokens issued by such banks.

Also on Wednesday, the U.S. regulator of credit unions, the National Credit Union Administration, proposed a rule governing how firms can apply to become stablecoin issuers. It's an opening step toward implementing last year's Guiding and Establishing National Innovation for U.S. Stablecoins (GENIUS) Act — the crypto industry's first major legislative win.

In the meantime, the crypto sector is now watching a policy race between Atkins' SEC and Senate lawmakers working on the Clarity Act to regulate U.S. crypto markets. With recent setbacks dragging on the Senate's progress, Atkins' agency may take a lead in establishing digital assets rules.

Read More: House Democrats slam SEC for dropping crypto cases with Trump ties