Complicating the matter for senators is the Trump campaign’s decision to not engage, so far, in the traditional transition process, having declined to sign agreements with the federal government that would launch FBI background checks of nominees, among other standard steps before confirmation hearings.

Even before taking office, Trump is challenging the Senate, in particular, to dare defy him over the nominations of Matt Gaetz, Robert F. Kennedy Jr. and other controversial choices for his Cabinet and administration positions.

The president-elect is testing the loyalty of Republican in Congress, leaving even his close allies nervous about the unpredictability and upheaval to come.