Final answer:
The federal government's role in social policy management has decreased since the late twentieth century with the advent of new federalism under Presidents Nixon and Reagan, leading to a devolution of power to states.
Step-by-step explanation:
The role of the federal government in the implementation of social policies has decreased since the late twentieth century. During President Nixon's and President Reagan's administrations, a movement known as new federalism sought to restore states' prominence in policy areas previously dominated by the federal government. This era saw the introduction of general revenue sharing programs and the Omnibus Budget Reconciliation Act of 1981, which consolidated federal grant programs related to social welfare to offer states more flexibility in their use of federal funds. This shift towards devolution, transferring certain powers back to the states, has caused substantial changes in how social policies are managed and implemented.
While the federal government still has significant influence, through power to pass and fund policies, the tendency has been towards giving states greater discretion, as evidenced by the Personal Responsibility and Work Opportunity Reconciliation Act in 1996, known as the welfare reform bill. Despite initial substantial federal involvement in creating social welfare programs during the New Deal and Great Society eras, modifications in federalism through policies advocating for administrative efficiency and improved policy outcomes have enabled states to mold these social policies more closely to their individual needs and preferences.