The main purpose of this legislative proposal is to amend the U.S. Constitution to ensure that only citizens of the United States can vote in federal elections. This amendment aims to clarify and reinforce the eligibility requirements for voting in elections for President, Vice President, and members of Congress. The key provisions of the proposed amendment state that only U.S. citizens are allowed to vote in federal elections, which includes primaries and general elections for the President, Vice President, and members of Congress.