The jibe, like her entire campaign, is exhilarating to Democrats who have no patience for the incrementalism that governing in a big, diverse and closely divided democracy requires.

There is a valid argument, borne out by polling and common sense, that a proposal to abolish the private insurance that covers 180 million Americans might be too radical a change to make all at once. It also hands President Trump a huge cudgel with which to flay Democrats in a race that promises to be close.

But Warren has put critics of her grand plans on the defensive in much the same way Barack Obama put Hillary Clinton on the defensive in 2008, when she argued that Obama’s plans were fantastical in the real world of Washington.

A big aspirational message is more satisfying than a cramped, political one. Warren is positioning herself as Big Change versus the status quo. Yes We Can versus No We Can’t.