Mr. Vought, an architect of Project 2025 who served in the first Trump administration, will be at the center of President Trump’s plans to upend the federal bureaucracy.

WASHINGTON — The Senate voted along party lines Thursday to confirm Russell Vought as the next head of the Office of Management and Budget despite fierce pushback from Democrats. Although Democrats have been divided over various Trump nominees, they unified in opposition to Vought.

Democrats protested Vought’s nomination overnight Wednesday on the Senate floor, with several referring to him as Trump’s “most dangerous nominee.”