The US Constitution
This is a federal constitution. Federalism is the most important idea for liberty. You must maximize your choices and you need meaningful choices, made against a cultural background. Federalism requires such moral correctness that it makes it the most difficult system to maintain. Federalism always fights consolidation.
States had a positive duty to intervene between citizens and the central government when unconstitutional acts were attempted. The Principles of ‘98 (The Kentucky Resolutions) were used for interposition and nullification. The 10th Amendment was the foundation of America. States were sovereign. Each state knew that it had a right to secede from the Federal Constitution because there was no time limit, like ninety-nine years, placed upon the compact.
Federalism was never restored. The states all looked to the Federal level to see what their rights were. Centralization was the process of modernity.
From the 2001 History of Liberty seminar.