The response to the coronavirus increasingly risks trampling on the Constitution, from government restrictions on the First Amendment freedom of assembly to the related freedom of religion. Now there's news that the governor of Rhode Island considered closing her state's border with Massachusetts. The governor, of whom I am generally a big fan, stopped short of ordering the border closed. That is a good thing, because she'd have collided pretty hard with the Interstate Commerce Clause in Article I of the Constitution, which gives Congress the power "to regulate commerce...among the several States." When states have argued that that language in the Constitution grants Congress a power that is non-exclusive—in other words, that Congress can regulate interstate commerce, but a state also has that power—the federal courts have generally told them to get lost.
Had the governor gone ahead and shut the border, it would have raised some interesting issues. Suppose the Boston Red Sox wanted to call a player up from their AAA Pawtucket farm team. Perhaps it is a good thing the Pawsox are decamping to Worcester, Massachusetts, to allow such call-ups eventually without risk that they might be interfered with by a border closure. Are Bostonians to be prevented from attending the Newport Jazz Festival? Could one evade the border closure by simply traveling through Connecticut? What would Massachusetts residents do in the summer without Del's lemonade, Narragansett beer, and all the essential equipment available at the Ocean State Job Lot? If some latter day Anne Hutchinson (for whom the Hutchinson River Parkway is named) tried to flee Boston for the relative religious freedom of Roger Williams' Rhode Island, would she be turned away at the border? If people from Massachusetts try to sneak into Rhode Island, how does the governor, a Democrat, propose to stanch the flow? With a Trump-style wall?