WASHINGTON – President Joe Biden has assembled the most aggressive antitrust team in decades, stacking his administration with three legal crusaders as it prepares to take on corporate consolidation and market power with efforts that could include blocking mergers and breaking up big companies.

Biden's decision this past week to name Jonathan Kanter to lead the Justice Department's antitrust division is the latest sign of his willingness to clash with corporate America to promote more competition in the tech industry and across the economy. Kanter has spent years as a lawyer fighting behemoths like Facebook and Google for rival companies.

If confirmed by the Senate, he will join Lina Khan, who helped reframe the academic debate over antitrust and now leads the Federal Trade Commission, and Tim Wu, a longtime proponent of breaking up Facebook and other large companies, who is now special assistant to the president for technology and competition policy.

The appointments show both the Democratic Party's renewed antitrust activism and the Biden administration's growing concern that the concentration of power in technology, as well as other industries such as pharmaceuticals, agriculture, health care and finance, has hurt consumers and workers and stunted economic growth.

They also underscore that Biden is willing to use the power of his office and not wait for the tougher grind of congressional action, an approach that is both faster and potentially riskier. This month, he issued an executive order stuffed with 72 initiatives meant to stoke competition in a variety of industries, increase scrutiny of mergers and restrict the widespread practice of forcing workers to sign noncompete agreements.

Outside groups and ideological allies of the administration warn that if Biden hopes to truly follow in the footsteps of his antitrust idols, Presidents Theodore Roosevelt and Franklin Roosevelt, he has to push for sweeping legislation to grant new powers to federal regulators, particularly in the tech sector. The core federal antitrust laws, which were written more than a century ago, did not envision the kind of commerce that exists today, where big companies may offer customers low prices but at the expense of competition.

The administration has quietly supported legislation working its way through the House, but it has not yet sought to lead a congressional antitrust push in the way Biden has on infrastructure, child care and other components of his $4 trillion economic agenda.

That could prove problematic if judges continue to strike down actions by the Justice Department, the FTC or other agencies.

Last month, a federal judge threw out an FTC suit against Facebook, saying the agency had not made a persuasive argument that the company is a monopoly and directing it to better justify its claims. Khan faces her first big test when she refiles that lawsuit, and on Friday the agency asked the court for more time.

Biden's antitrust picks argue that Facebook, Google and Amazon have monopoly power and have used their dominant positions in social media, search and online retail to squash competitors, leaving consumers with fewer options, even if that doesn't result in higher costs.

The companies and some economists disagree. Facebook points to TikTok, Snap and Twitter as examples of competitors, and Amazon argues it has just 5% of all retail sales in the United States, despite an eMarketer research study showing that 40% of all online retail sales occur on its platform.

Biden and his aides have cast his embrace of a "trustbuster" mentality as a crucial step toward rebalancing the economy not only to drive down prices but to fuel more competition and create high-paying jobs.

Corporate America is already fighting Biden's efforts. Google, Facebook and Amazon have filled their legal teams with antitrust experts, hiring veteran government antitrust officials in recent years. Facebook and Amazon have petitioned for Khan's recusal from antitrust matters related to their companies. They say Khan, who worked on a House antitrust investigation of digital platforms, comes with prejudgments about their corporations. Critics of Kanter, a private antitrust lawyer, point to his past representation of Microsoft and News Corp as conflicts of interest as the Justice Department wages its court battle against Google.

Biden's moves reflect the growing influence of a movement to restrain corporate power that has spread from progressive scholars and liberal leaders such as Sen. Elizabeth Warren, D-Mass., to some of the most conservative Republicans in Congress.

Thomas Philippon, an economist at New York University, concluded in 2019 that rising market concentration had hurt the U.S. economy and cost the typical American $5,000 a year. Administration officials repeatedly cite that statistic to support Biden's recent executive order.

Cracking down on market concentration and working to promote competition "can make an enormous difference in the lives of millions of people in this country," Bharat Ramamurti, a deputy director of Biden's National Economic Council and a former aide to Warren, said in an interview.

The approach contrasts sharply with the view of regulators during the Obama administration.

The number of merged hospitals quadrupled during President Barack Obama's first term, leaving millions of patients with fewer choices and higher prices for medical care.

Biden has directed federal regulators to consider a harder line against corporate consolidation in hospitals, health insurance, meat processing and tech, which could include revisiting past mergers that were approved.

And his antitrust regulators are trying to unwind mergers approved during the Obama years. The Federal Trade Commission's recent lawsuit to break up Facebook centers on the company's purchases of Instagram in 2012 and WhatsApp in 2014. The agency did not block the mergers.