Now we know why Elizabeth Warren took so long to release the financing details of her Medicare-for-All plan. The 20 pages of explanation she released Friday reveal that she is counting on ideas for cost-savings and new revenue that are a fiscal and health-care fantasy.

You certainly can’t criticize the new Iowa Democratic caucus front-runner for lack of ambition. Despite criticism from fellow Democrats, she is sticking to her plan for a government takeover of American health care, including the elimination of private insurance...