I think all Dems will eventually come around to a multi payer system it makes better sense fiscally and politically.
Obamacare for all would be a very good idea. One dillema I see, however, is how to appropriately balanve punishing people who choose to increase their health risk--by smoking/being fat--with general compassion. Furthermore, any expansion of government supported healthcare must be accompanied by bringing down America's absurd healthcare costs
Regardless, I don't think this should be the primary objective of the next Democratic administration. The past two Days presidents squandered their majorities on healthcare. Obamacare is an acceptable system, and it's time to prioritize more pressing issues like tax reform, immigration reform, criminal justice reform, and infrastructure.