Mr. Biden has prodded the Agriculture Department to investigate large meatpackers that control a significant share of poultry and pork markets, accusing them of raising prices, underpaying farmers — and tripling their profit margins during the pandemic. As gas prices surged, he publicly encouraged the Federal Trade Commission to investigate accusations that large oil companies had artificially inflated prices, behavior that the administration says continued even after global oil prices began to fall in recent weeks…

Corporate culpability for rising prices remains unclear. Inflation is at a 40-year high because of pandemic-related factors such as broken supply chains and high demand for goods from consumers still flush with government-provided cash. But as the price increases have spread across sectors, including food and gasoline, the administration has come under increasing pressure to find ways to respond.

White House officials concede that their antitrust moves are unlikely to reduce costs for U.S. businesses or consumers immediately. The efforts, they say, will be more effective down the road. But the rise of inflation has given the White House an opportunity to take action that Democrats have long encouraged, and that Mr. Biden made an early focus of his tenure: using the power of government to break up monopolies and promote economic competition.