Securities and Exchange Commission Chairman Jay Clayton might be in for the fight of his life to secure the nomination to become the next United States Attorney for the Southern District of New York.

Clayton, who has provided a steady hand at the SEC for the past three years, reportedly made overtures to the Trump administration that he would like to return home to Manhattan and become the federal prosecutor that handles more securities and financial fraud related crimes than any other. He got part of his wish when President Donald Trump nominated him.

But the Trump administration’s handling of the removal of the current prosecutor, Geoffrey Berman, has been anything but smooth. Over the weekend, Trump and Attorney General William Barr orchestrated the ouster of Berman, who had held the position since 2018. Berman initially refused to step down, until he was officially fired. In his place, Barr named the deputy U.S. attorney, Audrey Strauss, as acting head.

Berman, during his two years as the U.S. Attorney for the Southern District of New York, pursued a number of investigations into people in Trump’s inner circle, including a successful prosecution of his personal attorney, Michael Cohen; and several pending and completed investigations into his current attorney, Rudy Giuliani. Many wondered if Trump and Barr removed Berman because his office pursued those investigations.

The resulting controversy has made it much less likely that Clayton will even get a nomination hearing in Congress. The nomination is starting to look less like a plum posting and more like a hand grenade.

Several high-profile Democrats called on Clayton to withdraw his nomination, including the two New York senators—Chuck Schumer and Kirsten Gillibrand—who could block his nomination using a procedural move.

Schumer said Clayton should should withdraw his nomination to “save his own reputation from overnight ruin.”

Sen. Lindsey Graham (R-S.C.), a close Trump ally who is chairman of the Senate Judiciary Committee—which would approve Mr. Clayton’s nomination—suggested in a statement that he would allow New York’s two Democratic senators to thwart Clayton’s nomination. Should Congress delay until November, Clayton would only be successful in his quest for the post if Trump wins re-election. If his nomination is to be approved, it needs to happen fast. And that seems unlikely.

All that aside, what would it mean for the SEC if Clayton left?

His three-year tenure in charge of the SEC has been relatively quiet. When Clayton first took command in 2017, he proclaimed the agency’s top priority would be to help and protect Main Street investors. Unlike other Trump-appointed regulators—like Consumer Financial Protection Bureau Director Kathleen Kraninger agreeing with claims in a lawsuit that her agency is unconstitutional, or Federal Trade Commission Commissioner Rohit Chopra saying the FTC has been too soft on Big Tech—Clayton has generally avoided controversy and kept a low profile.

Since Clayton became chairman, the SEC has kept up a steady drumbeat of securities-related fraud prosecutions, while also going after cryptocurrency speculators—Clayton has clearly sided with investors over innovators in the cryptocurrency space.

The SEC has also issued a number of large whistleblower awards this year, but most stemmed from cases launched before Clayton headed up the agency.

Clayton’s advocacy of the Regulation Best Interest (Reg BI) rule package will likely be his enduring legacy, said Chester Spatt, professor of finance at Carnegie Mellon University’s Tepper School of Business and former chief economist at the SEC.

Reg BI is intended to enhance the quality and transparency of retail investors’ relationships with investment advisers and broker-dealers, bringing the legal requirements and mandated disclosures in line with reasonable investor expectations while preserving access (in terms of choice and cost) to a variety of investment services and products.

Reg BI takes effect June 30, and of course, a lot will depend on how the SEC interprets it. The new regulation also faces a legal challenge from seven states, another hurdle that a reconstituted SEC would have to face without Clayton at the helm.

The leader of a nonprofit group founded to promote the public interest in the financial markets was critical of Clayton’s record, particularly on protecting investors.

“While the Chairman often says that he worries about ’Mr. and Mrs. 401k’ and protecting Main Street investors, his record shows he has been protecting the profits of Wall Street and his former clients,” said Dennis M. Kelleher, president and CEO of Better Markets, in a statement. “The fact that almost all of his actions are cheered by the financial industry, and Wall Street’s biggest banks in particular, while being opposed by all or almost all investor, consumer protection and financial stability advocates is a red flag clearly indicating who he really has been looking out for.”

Kelleher was also critical of Reg BI, which he said “failed to require a fiduciary duty putting investors’ best interests first, which protected Wall Street’s business models and profits, not investors.”

Perhaps the most controversial thing Clayton has done during his tenure is pick an ongoing, high-profile fight with Tesla CEO Elon Musk, a feud that has dragged on for years despite the SEC levying a pair of $20 million fines against Musk and the company in 2018.

Clayton’s departure could spur the SEC in a new direction, depending on whom is nominated to take his place. Clayton is both the SEC’s chairman and its lone independent member. Trump recently nominated Democrat Carolyn Crenshaw to fill the SEC commissioner slot left vacant when Commissioner Robert Jackson resigned earlier this year.

The biggest problem for the SEC should Clayton leave is a lack of leadership, Spatt said.

“Things inevitably slow down when there is a change at the top, and regulators are no different,” he said.

Before taking over the helm of the SEC, Clayton worked as a corporate lawyer for Sullivan & Cromwell, representing some of the country’s largest financial institutions.

He has no experience as a prosecutor, which makes his nomination all the more curious. That gap in his resume might have made his confirmation hearings before Congress uncomfortable. Clayton is stepping into a highly charged political fight that he may never have envisioned or welcomed.

Spatt says there is perhaps no more U.S. Attorney’s office in the country that is more connected to the SEC that the Southern District of New York, because of the office’s handling of securities and financial related crime.

“It’s not any random district. It is, in fact, the most important district in regard to financial crimes,” he said. “[Clayton] has demonstrated an ability to manage large complex matters and provided useful guidance. There’s a first time for everything.”