The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA)
Says that states receiving welfare can pay to another state the amount it pays to cover a citizen that has moved from the former state into the the ladder state for one year
Example: If a person is on welfare in Kansas and they move to California and they want Califonia's better welfare Kansas has to pay California the original amount of welfare to cover the moved person for one year.
They stated that, under the Fourteenth Amendment, citizens who have moved to a new state must be treated the same as citizens who have lived there for longer than one year because enforcing the PRWORA could discriminate certain citizens of the same larger country.