What gives the Constitution the final word in regards to this country's legal code?

The Constitution serves as the supreme law of the land, establishing a framework for the U.S. legal system and ensuring that all laws and governmental actions must conform to its principles. Its final authority is upheld by the Supremacy Clause, which asserts that federal law takes precedence over state laws and constitutions. Additionally, the judicial system, particularly the Supreme Court, interprets the Constitution, ensuring its application and resolution of conflicts within the legal code. This combination of supremacy and interpretation grants the Constitution its ultimate authority in legal matters.