Final answer:
To modify the Constitution, an amendment must be proposed either by two-thirds of both Congress chambers or by a national convention called by two-thirds of the state legislatures. Proposing an amendment is the first step in a two-step process defined by Article V of the Constitution, which also requires ratification by three-fourths of the state legislatures or conventions.
Step-by-step explanation:
To modify the Constitution, an amendment must first be proposed either by two-thirds of both chambers of Congress or through a convention called by two-thirds of the state legislatures. The amendment process is clearly defined in Article V of the Constitution and represents a two-step procedure: proposing and then ratifying the amendment.
Proposing an Amendment
An amendment can be proposed by a two-thirds supermajority vote in both the House of Representatives and the Senate, which is the approach that has been used for all current amendments to date. Alternatively, if two-thirds of the state legislatures call for one, Congress must convene a national convention to propose amendments, although this method has never been successfully used.
Ratifying an Amendment
Once an amendment has been proposed, it must be ratified by three-fourths of the state legislatures or by conventions in three-fourths of the states. This requirement ensures a broad consensus is needed before any changes to the Constitution are adopted.
The amendment process is intentionally rigorous to ensure that changes to the foundational document of the nation reflect a broad agreement across the diverse states.