The Senate confirmed Russell Vought as White House budget director on Thursday night, putting an official who has planned the zealous expansion of President Donald Trump's power into one of the most influential positions in the federal government.

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.

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.