Chuck Schumer aspires to raise taxes on every rich person in America, save one protected class: coastal progressives. The Senate Minority Leader recently styled part of President Trump’s tax plan as “a dagger aimed at the heart” of New Yorkers. Like many other Democrats, he’s apoplectic about a plan to end the state and local tax deduction.

Taxpayers who itemize—about one in three do so—can deduct income and property taxes paid to state and local governments from their federal tax liability. The White House in its recent tax...