Final answer:
A public policy program that involves collaboration between national, state, and local policymakers is an example of cooperative federalism, which allows for a blended layering of government activities and shared concurrent powers.
Step-by-step explanation:
A public policy program on which national, state, and local policymakers collaborate is an example of cooperative federalism. Under this style of federalism, both levels of government coordinate their actions to address national issues. The era of cooperative federalism is characterized by a blending of government layers, similar to a marble cake, which leads to concurrent powers between the states and national government. These concurrent powers include activities such as taxing, borrowing, enforcing laws, and establishing court systems. Cooperative federalism has seen the national government increase its influence in areas traditionally managed by states through various strategies, including the provision of block and categorical grants, and sometimes mandates. This collaborative approach has contributed to a nationalization of policies and has allowed for a degree of flexibility in the implementation of federal social welfare programs by state and local authorities.