Mary Jo White, head of the U.S. Securities and Exchange Commission, speaks during a Senate hearing in June. (Andrew Harrer/Bloomberg News)

Mary Jo White, the head of the Securities and Exchange Commission, on Monday announced that she would step down two years before the end of her term, clearing the way for President-elect Donald Trump to reshape the way Wall Street is regulated.

The resignation creates a massive opportunity for Trump early in his term to make changes to investor protections and other Wall Street regulations, part of what is widely expected to be a broad effort by the new administration to scale back what Republicans consider cumbersome federal rules that slow economic growth.

“In the long-term, it is going to be a big tilt towards free markets,” said Edward Mills, a policy analyst at investment bank FBR Capital Markets.

Trump and his advisers have taken aim at President Obama’s main regulatory response to the 2008 financial crisis — the Dodd-Frank Act, which tightened oversight of the financial industry. The most visible target is the Consumer Financial Protection Bureau, the watchdog agency that has pursued stricter rules governing debt collection, payday loans and overdraft fees.

But Trump and his advisers have also targeted a broad swath of consumer issues over the course of his campaign, from rules for online privacy to conflicts of interest among financial planners. Beyond the SEC, he could also dramatically alter the ideological landscapes at key agencies such as the Federal Communications Commission and the Federal Trade Commission, whose top officials are nearing the end of their terms.

Consumer advocates say they are bracing for a fight. Public Citizen has warned that it is prepared to sue over moves that it deems questionable. The American Civil Liberties Union was flooded with donations after it posted an ad bearing Trump’s image and the terse challenge “See you in court.” And U.S. Public Interest Research Group (U.S. PIRG) recently hired a litigation director and is beefing up its state and local field operations.

“We’ve always been at DEFCON 2, and now we’re going to DEFCON 1,” said Ed Mierzwinski, director of the consumer program and senior fellow at U.S. PIRG. “Defense is a lot of work.”

After the 2008 severe economic downturn, lawmakers and regulators across the government undertook the largest wave of reforms aimed at safeguarding American consumers since the Great Depression. The efforts were intended to curtail predatory lending, enhance transparency within the industry and level the playing field for ordinary households dealing with complex financial products.

But the movement has generated massive costs across the banking sector. A recent report by the conservative American Action Forum estimated that complying with the law has cost the industry $36 billion and 73 million hours in paperwork.

More importantly, Republicans have blamed the Dodd-Frank Act for impeding economic growth and dampening innovation. In addition, lenders wary of running afoul of new laws have curtailed credit to those with blemished financial histories.

“If we want strong economic growth and more freedom, we must empower Americans, not Washington bureaucrats,” Rep. Jeb Hensarling (R-Texas), chairman of the House Financial Services Committee, said this summer when he released a blueprint for undoing Dodd-Frank.

On the campaign trail, Trump made a blanket promise to overhaul the government’s entire regulatory code and halt the approval of new rules “not compelled by Congress or public safety.” He said Dodd-Frank should be “dismantled” but did not detail how.

For consumers, the centerpiece of the legislation is the Consumer Financial Protection Bureau, which recently notched a major victory when it fined Wells Fargo $100 million for allegedly opening fake accounts for its customers. Consumer advocates say the upheaval could threaten significant new rules for payday lenders, auto title loans and debt collectors. The bureau has also proposed banning what’s called mandatory arbitration clauses that limit class-action lawsuits from consumers.

In June, Trump met with Hensarling to discuss the lawmaker’s plan for disbanding Dodd-Frank and reorganizing the Consumer Financial Protection Bureau, according to a Hensarling aide. His plan calls for restructuring the agency so that it would be led by a five-member commission instead of a single director and changing the way it is funded.

But even if Trump does nothing, the agency still could face significant change. Last month, a federal appeals court ruled that the agency must be restructured so that the director can be removed at will. And no matter what happens, Director Richard Cordray’s term ends in 2018, allowing Trump to pick his successor.

“We don’t want to go back to a system that led us into the mortgage crisis,” said Lauren Saunders, associate director at the National Consumer Law Center. “I hope we have all learned from our mistakes.”

Consumer advocates are also worried about the SEC, which has two commissioner positions open. The SEC tightened oversight of asset managers and other Wall Street firms following the financial crisis and is working on rules to promote more disclosures about executive pay. It is also reviewing the exploding use of exchange-traded funds, a popular and relatively new financial product that many people use to invest in stocks.

“The SEC is one of the central cops on the beat in the financial markets, making sure that ordinary investors are treated fairly,” said Marcus Stanley, policy director at Americans for Financial Reform. If the SEC is weakened, “it is ordinary consumers that will get hurt the most.”

At the Federal Trade Commission, Chairwoman Edith Ramirez’s term expired last year, but she has remained amid Senate gridlock in confirming new appointments. Only three seats at the agency’s five-member commission are filled, and Trump could name the lone Republican, Maureen Ohlhausen, as chairwoman. If he fills the vacant seats as well, the GOP would enjoy a majority.

His choices will help determine how the Federal Trade Commission will steer investigations on topics including data security and antitrust issues and its approach on enforcement. Democratic Commissioner Terrell McSweeny says that who Trump appoints will “speak volumes about the direction of the agency.”

The Federal Communications Commission faces a similar predicament. Though Chairman Tom Wheeler’s term does not end for two years, Trump can appoint a new chairman within the five-member commission that leads the agency, tilting the balance of power.

One big question is whether he would appoint officials to pull back new privacy rules passed by the Federal Communications Commission last month that force Internet providers to give consumers a say in how their most sensitive personal data is used and shared. Wheeler and the agency’s two other liberal commissioners pushed the policies through over stiff Republican opposition.

And last week, the agency fired a warning shot at AT&T over its practice of letting wireless customers stream as much DirecTV (which it owns) as they want on their mobile devices without counting against data limits. Regulators’ questions about the tactic, known as “zero-rating,” are likely to become moot if the Trump administration rolls back the regulations that allow the agency to probe the practice.

Still, the letter to AT&T is a sign that Wheeler intends to push forward with his agenda in the next several months.

Wheeler “is going to keep working as long as he’s being paid by the American people to do this job,” said Gene Kimmelman, president of the consumer advocacy group Public Knowledge.

Consumer advocates said that rolling back regulatory safeguards enacted since the financial crisis would undermine Trump’s appeal to the working-class voters who helped sweep him into the Oval Office. Public Citizen President Robert Weissman said his group plans to highlight any discrepancies that may emerge between Trump’s rhetoric during the campaign and his policies once in office.

So far, he said, Trump’s appointment of lobbyists and Wall Street bankers to his transition team has not been encouraging.

“There are no illusions on our side about what we’re looking at, and we’re gearing up,” Weissman said.

Brian Fung, Andrea Peterson and Jonnelle Marte contributed to this report.