One example was during the Marbury vs. Madison case in 1803
where the court declared that the Judiciary Act of 1789 was contradictory with
the Constitution making it invalid. This
was because the Court had the authority to assert that an act of Congress to be
annulled if it was revealed to conflict with the Constitution.
The fact that leaders get to contest in an election to win the mandate of the people so that they can lead ensures that they are responsive to their wishes. This is because voters will naturally elect people that are sympathetic to their issues
