The debate over the future of the health care system will continue to be a key issue on the presidential trail in 2020, but as Tuesday’s winnowed-down Democratic debate highlighted, Sen. Bernie Sanders (I-VT) is now the lone top-tier presidential candidate still calling for a quick transition to Medicare for All, while the other Democratic candidates argue that their policy ideas are just as bold. In Congress, Democratic leadership has given no hints as to when, or whether, they might...