President-elect Donald Trump, who moved the U.S. Supreme Court dramatically rightward in his first term, may get a chance to rejuvenate its 6-3 conservative majority by replacing some or all of its three most senior conservatives with younger jurists - and perhaps even expand it if a liberal justice leaves.

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.