Involved Voters who want to understand the U.S. Constitution better should consider reading Keeping Faith with the Constitution (Liu, Karlan, Schroeder; Oxford University Press, 2010). The book describes a "constitutional fidelity" approach to the document and lays out the limitations of "originalist" and "strict construction" approaches.
In the words of the great Chief Justice John Marshall, our Constitution is "intended to endure for ages to come, to be adapted to the various crises of human affairs." To preserve the meaning and authority of the Constitution and keep it a living document, it's necessary to add precedent, historical experience, practical consequences and societal change to attempts to determine the original understanding of the text.
As the book's authors point out, the U.S. Constitution contains "the basic structure of government and some of its important procedures while expressing our commitment to certain core values: liberty, equality, and democracy."
A "constitutional fidelity" approach brings advances such as Amendment XIX (ratified in 1920) which states:
The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.Such an amendment is faithful to the core Constitutional values of liberty, equality, and democracy, but is not something those relying solely on the original intent of the Framers of the 1789 Constitution would make a case for.
Congress shall have power to enforce this article by appropriate legislation.
The U.S. Constitution has been successful in preserving our nation because it is flexible enough to allow government to adjust as its citizens progress toward including all human beings in their vision of liberty, equality, and democracy.