Commentary The most important checks and balances in our constitutional system derive from the split authority between the federal government and the states. As the federal government has grown in power, state “pushback”—which James Madison called “interposition”—has become more important than ever. In my March 14, 2021, Epoch Times essay, I listed common methods of interposition. States contemplating interposition usually should act in cooperation with other states. One kind of cooperation common in recent years has been the joint interstate lawsuit. This essay outlines how other methods of cooperation work. Conventions of States A convention of states (or convention of the states) is a meeting of state delegations, each with equal voting power. The Constitution’s framers adopted this device as a way to propose amendments to the document. For example, in a recent Epoch Times essay, I explained how a convention could propose an amendment reclaiming public health policy from …