In Shapiro v. Thompson, the U.S. Supreme Court ruled in 1968 that states cannot constitutionally deny welfare benefits to residents who have not lived within their jurisdiction for at least a year. The case involved three separate appeals from Connecticut, Pennsylvania and Washington D.C., where individuals were denied welfare assistance due to residency requirements stipulated by local laws. These laws required applicants to be residents of the state or district for at least one year before they could apply for public assistance benefits. The court held these statutes unconstitutional on grounds of violating the Equal Protection Clause of the Fourteenth Amendment as well as inhibiting freedom of movement protected under Article IV's Privileges and Immunities Clause.

In the dissenting opinion for Shapiro v. Thompson, Justice Harlan argued that the majority's decision was an overreach of judicial power and a misinterpretation of the Equal Protection Clause. He contended that it is not within the Court’s purview to decide whether Connecticut’s one-year residency requirement for welfare benefits is wise or unwise, but rather if it violates specific constitutional prohibitions. He believed this law did not violate any such prohibitions as states have traditionally had broad powers in determining their own public welfare policies and should be allowed some flexibility in managing their resources. Furthermore, he disagreed with the majority's view that this law created a "right to travel" issue; instead, he saw it as an economic regulation which does not infrally on fundamental rights or discriminate against particular groups. Therefore, according to him, it should only require rational basis review - a standard which he believes Connecticut’s policy would pass.