In recent years, new administrations have not been shy about disavowing positions taken by their predecessors.

Dozens of vacancies could open in the appeals courts that decide on pressing and far-reaching issues, from financial regulations to abortion.

After his election victory, President-elect Trump could appoint more conservative justices to the Supreme Court. There are suggestions from some Democrats that Justice Sonia Sotomayor should retire soon to pave the way for a younger liberal justice.