While House Republicans and Trump appear to be aligned in their desire to investigate Biden’s fitness to serve, there is some frustration brewing among congressional committees about how quickly the Trump administration is responding to some of their requests, according to multiple GOP congressional sources familiar with the matter.

The Republican-led House Oversight Committee on Thursday took its first step in its new investigation of the White House's handling of former President Biden's health: Demanding testimony from his doctor and his top advisors.

Sen. Ron Johnson (R-Wis.), the chair of the Senate Permanent Subcommittee on Investigations, is writing letters to two dozen former senior Biden administration officials to appear before his committee to answer what they knew about former President Biden’s health problems in light of allegations that White House officials deliberately kept his cognitive and physical