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.

Vought was confirmed on a party-line vote of 53-47 after Democrats had exhausted their only remaining tool to stonewall a nomination — holding the Senate floor.

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