Trump Is Expected to Upend Biden Labor Policies Favoring Unions

Joseph R. Biden Jr. promised to be the most pro-labor president in history. He embraced unions more overtly than his predecessors in either party, and filled his administration with union supporters.

Labor seemed to respond accordingly. Filings for unionization elections spiked to their highest level in a decade, as did union victories. There were breakthroughs at companies like Starbucks and Amazon, and unions prevailed in organizing a major foreign auto plant in the South. A United Automobile Workers walkout yielded substantial contract gains — and images of Mr. Biden joining a picket line.

As Donald J. Trump prepares to retake the White House, labor experts expect the legal landscape for labor to turn sharply in another direction.

Based on Mr. Trump’s first term and his comments during the campaign — including his praise for Tesla’s chief executive, Elon Musk, for what he said was Mr. Musk’s willingness to fire striking workers — these experts say the new administration is likely to bring fewer challenges to employers who fight unions.

“There will be a concerted effort to repeal pro-worker N.L.R.B. precedents,” said Heidi Shierholz, a senior Labor Department official during the Obama administration, referring to the National Labor Relations Board.

Experts like Ms. Shierholz, who is now president of the liberal Economic Policy Institute, said they also expected the Trump administration to ease up on enforcing safety rules, to narrow eligibility for overtime pay and to make it harder for gig workers to gain status as employees.