During the recent controversy over Indiana’s RFRA, some states banned non-essential travel by state employees to Indiana. (What would constitute essential travel to Indiana was left unsaid.) This got me thinking about whether there are any constitutional limits on a state–acting as a market participant–boycotting another state.
An example of a state’s broad authority to discriminate in favor of its residents is that tuition charged to in-state students can be lower than for out-of-state students. Suppose, though, that a state said: “We will not admit any students from State Y to state universities because of State Y’s policy on something.” Could this be done? Maybe this would flunk rational basis review, but one could say in favor of rationality that a state wants to express its outrage at State Y’s policy. The Dormant Commerce Clause is not at issue because the state is acting as a market-participant rather than as a regulator. Is there a Privilege or Immunities Clause claim here? Maybe, but why?