How should state governments treat the laws and court decisions of other states?

State governments in the United States are expected to treat the laws and court decisions of other states with a level of respect and acknowledgment under the principle of "Full Faith and Credit." This principle is mandated by the Full Faith and Credit Clause of the U.S. Constitution, specifically Article IV, Section 1, which states:

"Full Faith and Credit shall be given in each State to the public Acts, Records, and judicial Proceedings of every other State."

What this means in practical terms is that each state must recognize the laws, public records, and court decisions of the other states, and cannot disregard them arbitrarily. For example, a marriage or divorce that is legally recognized in one state must be recognized by all other states. Similarly, if a person is judged in a court in one state and a decision is rendered, other states are expected to uphold that judgment.

However, the application of the Full Faith and Credit Clause is not absolute. States do have some flexibility and are not required to enforce another state's laws if those laws are in direct contradiction with their own public policy. For instance, a state with strict gambling laws may not enforce a gambling debt from a state where gambling is legal.

Additionally, Congress has the power to regulate the manner in which the states grant full faith and credit to each other's laws and decisions, which can slightly alter how this clause is applied.