The Kaus-Yglesias-Shrum-Kucinich view of health care:

Another resonant point isn't yet CW, though--[Bob Shrum] argued that all the Democratic health care plans are too complicated, that whoever is the Dem candidate should just say he or she plans to let everyone join Medicare and leave it at that. People know Medicare. It's hard to attack Medicare as "socialized medicine." ... P.S.: I've never quite understood why this politically appealing position is fatally flawed on policy grounds. (If there are problems with Medicare, fix them! Surely they need to be fixed even if the program doesn't get extended to younger Americans.)

I think that's right. And if you don't have the votes for "Medicare for All" then you can take "Medicare for Everyone Over 50." If you don't have the votes for that, you can take "Medicare for Everyone Over 55." Then after the next election you come back and ask for more. And then more. And more. But you give the public a marker -- "Medicare for All." Sure, it's more slogan than program, but it's a good slogan.