In the first century or so of our national existence, one of the Constitution’s provisions that was most often at issue was the Contract Clause. But following New Deal era decisions that eviscerated it, hardly any cases have since centered on it. The clause has been so forgotten that few Americans even know it’s there, in Article I, Section 10, reading, “No state shall pass any law impairing the obligation of contracts.” The Constitution’s drafters had good reason to include that language, meant to assure people that contracts would be inviolate. During the years under the Articles of Confederation, the...