Tax Reform Take 2: The States

After federal success, the next reform targets are high-tax states.

Congress passed the most sweeping tax reform since 1986 on Wednesday, and with any luck that success for the country will trigger a new reform debate in many states. To wit, how much will they have to cut income-tax rates to retain and attract the high-income earners who finance so much of their state budgets?

You can figure out who most needs reform by the decibels of protest. Amid other apocalyptic warnings, New York Gov. Andrew Cuomo last weekend declared that the GOP bill’s limit on the state-and-local tax deduction will...