As the Supreme Court sees it, the Privileges and Immunities Clause of Article IV and the Commerce Clause of Article I serve the common goal of unifying the country economically. The primary purpose of the clause is to prevent states from placing unreasonable burdens on non-residents "in their pursuit of common callings within the state." The concern of the framers was that discrimination against non-residents by one state would lead to discrimination of the same sort by other states, to the detriment of the nation as a whole.
Clearly, however, the Constitution does not require states to treat residents and non-residents equally for all purposes. If this were so, non-residents could vote in another state's election, run for office in another state, or collect benefits from another state.
Justice Bushrod Washington, sitting as a circuit judge in the case of Corfield v Coryell (1825), first considered the meaning of Article IV's Privileges and Immunities Clause. Bushrod Washington concluded that the clause was meant to prevent discrimination concerning fundamental matters (such as the right to pursue an occupation in another state), but was not intended to prohibit distinctions between residents and non-residents in less fundamental matters such as opportunities for recreation. To a large extent, Washington's approach has been followed ever since.
Justice Bushrod Washington, nephew of George and author of the leading opinion on the meaning of Article IV's Privileges and Immunities Clause
Baldwin v Montana Fish & Game Comm'n (1978) considered Montana's great difference in fees charged Montana hunters and out-of-state hunters. The Court upheld the differential fees, finding recreational hunting not to be the sort fundamental activity within the conern of the Privileges and Immunities Clause.
In our two other cases, however, the Court found state attempts to restrict occupational opportunities within the state for non-residents to violate the clause. In Hicklin v Orbeck (1978), the Court struck down the "Alaska Hire Law," which gave Alaska residents a preference for jobs in the state's oil industry. And in Supreme Court of New Hampshire v Piper (1985), the Court voided a New Hampshire rule that limited admission to the state bar to New Hampshire residents. In both cases, the Court found that the states had failed to meet the high burden of justification for a law discriminating against non-residents with respect to a fundamental right. Discriminatory laws of this sort, the Court said, would only be upheld when the non-residents are "a peculiar source" of the "evil" the state is attempting to regulate and when the discrimatory law is the best way to get at the problem.
2. Would the Court uphold a total ban on hunting by non-residents? What about a ban on non-residents using state parks and beaches?
3. Would the Court uphold a state law that allowed vehicles with in-state license plates to travel 70 mph, but limited vehicles with out-of-state plates to 60 mph? What provision of the Constitution would provide the best basis for striking down such a law--the Privileges and Immunities Clause, the Equal Protection Clause, or the Commerce Clause?
4. Why were not non-residents competing for the jobs Alaskans might otherwise take "the peculiar source" of Alaska's problem of high unemployment in Hicklin?
5. Could a state limit state jobs to residents? For example, might a state insist that all professors in its state universities be residents of the state? (If such a law is constitutional, what happens to couples living near a stateline when the husband works for one state and the wife for another?)