Which body has the authority to admit new states to the Union?

The authority to admit new states to the Union is vested in Congress as a whole, which includes both the House of Representatives and the Senate. This power is stated in the U.S. Constitution, specifically in Article IV, Section 3. Congress has the ability to create new states and manage territories, ensuring that the admission process reflects the interests and consensus of the entire federal legislature.

This is vital because it represents a democratic process, allowing elected representatives to make decisions that impact the governance and distribution of states in the nation. The President does play a role in terms of signing a statehood bill into law, but the initial decision and legislative framework come from Congress. The Supreme Court does not have the authority related to state admissions; its role is primarily judicial rather than legislative.