What was the issue at the heart of the Marbury vs. Madison case?

The central issue in Marbury v. Madison was indeed the legality of the midnight appointments made by President John Adams. As his presidency was coming to an end, Adams appointed several federal judges, known as "midnight judges," to ensure that his political influence continued. When Thomas Jefferson took office, his Secretary of State, James Madison, refused to deliver the commission to William Marbury, one of the appointed judges, which led Marbury to seek a writ of mandamus from the Supreme Court.

The Supreme Court, led by Chief Justice John Marshall, ultimately faced the question of whether Marbury had a right to his commission and if the Court had the authority to force Madison to deliver it. This case became significant for establishing the principle of judicial review, allowing the Supreme Court to assess the constitutionality of acts of Congress or executive actions. Therefore, the case's core revolves around the consequences and legality of the last-minute appointments made by Adams and the subsequent actions taken by his successor's administration.