One key feature of the Constitution – the concept of federalism – was unclear when it was introduced, and threatened the Constitution’s ratification by those who feared the new government would undermine state sovereignty. In their famous essays in The Federalist, Alexander Hamilton and James Madison defended the Constitution and argued that state legislatures would sound the alarm if the national government exceeded its authority. They argued that through interposition state legislatures would effectively check the national government by mobilizing resistance should the government try to overreach. Resolutions passed by legislators could legitimately be considered an expression of the people that could then be shared with the state’s congressional delegation and other state legislatures. Hamilton’s and Madison’s advocacy for state legislatures as monitors of the equilibrium of the two levels of government under the Constitution was a rhetorical argument designed to address the objections of Anti-Federalists. At the time of the ratification debates, both men were deeply distrustful of state legislatures, yet needed to explain how the national government would not overwhelm the states.