The Supreme Court case King v. Burwell being argued March 4 is one of profound national importance. It challenges the legality of 75% of ObamaCare—the subsidies that the federal government has been paying to health insurers on behalf of enrollees in the 37 states that chose not to participate in ObamaCare.

Like most conservatives, I am hopeful about the court’s decision, expected in June. The law explicitly requires states to establish an exchange to unleash entitlement payments. Because ObamaCare’s central planning is unworkable...