*("major" is obviously a subjective term depending on who's using it.)
Until this weekend, "Medicare for All or Bust" seemed to be the most critical litmus test for any major 2020 Democratic Presidential candidate. No fewer than sixteen Democratic Senators co-sponsored Bernie Sanders' S.1804 "Medicare for All" single payer bill in September 2017, including five of the six U.S. Senators currently running for the 2020 nomination: Sanders himself, Cory Booker, Kirsten Gillibrand, Kamala Harris and Elizabeth Warren (the only Senator running who didn't cosponsor the bill was Amy Klobuchar.)
Recently, however, there have been a few interesting developments along the "Where do the Dem candidates stand on healthcare policy" front:
