Final answer:
Dual federalism became extinct due to the evolution towards cooperative federalism, which was necessitated by national crises requiring coordinated responses between state and national governments. National issues such as the Great Depression, civil rights movements, and economic management necessitated increased federal intervention, eroding the clear-cut boundaries of dual federalism.
Step-by-step explanation:
Dual federalism became extinct due to the transition towards cooperative federalism, a process marked by an increasingly active federal government in policy areas that were previously handled by states. This shift was necessitated by national crises such as the Great Depression and civil rights movements, where a coordinated national response was critical. As a result, there was an erosion of the clearly demarcated jurisdictional boundaries that had been characteristic of dual federalism. The changing nature of federalism is evidenced by the rise of the New Deal, where the national government's responsibilities expanded to manage and address national issues more directly.
Furthermore, intergovernmental relationships evolved to include strategies like block and categorical grants, meant to subsidize state and local costs of implementing federal policy programs. Over time, the need for national solutions to economic and social issues led to the expansion of federal powers and a blurring of the once distinct layers of government authority, akin to a marble cake rather than the layer-cake model of dual federalism.
The culmination of these factors led to dual federalism being supplanted by more integrated and cooperative approaches between state and national governments. During the administrations of Presidents Nixon and Reagan, attempts were made to decentralize and return some powers to the states, in what was termed new federalism. However, the legacy of cooperative federalism's approach to national problems made a long-lasting impact on the balance and nature of American federalism, making the distinct separation of powers under dual federalism obsolete.