What does the Preamble of the US Constitution describe?

The Preamble of the US Constitution serves as an introductory statement that outlines the fundamental purposes and guiding principles of the document itself. It emphasizes the intents of the Constitution, such as establishing justice, ensuring domestic tranquility, providing for the common defense, promoting the general welfare, and securing the blessings of liberty. This clear articulation of the purpose of government sets the stage for the specific powers and structures that follow in the body of the Constitution.

In contrast, the other options focus on specific components of governance that are detailed elsewhere in the Constitution. The powers of the legislative branch are laid out in Article I, while states' rights and the boundaries of presidential power are addressed in different parts of the document. Thus, while those topics are vital for understanding the full scope of the Constitution, they are not the focus of the Preamble itself.