Bruni column: Democrats have a politeness problem

Twice near the start of the last Democratic presidential debate, George Stephanopoulos of ABC News tried to pin Elizabeth Warren down on whether her vision for Medicare for All would require a middle-class tax increase. Twice she didn’t answer him. It was the perfect opening for one of the other contenders for the Democratic presidential nomination to charge her with evasiveness and force her to reckon fully with the costs of her ambitious plans and the profound difficulty of enacting them.