The "buy in" to Medicare doesn't do that, as Americans believe that people have the right to something if they pay for it, and particularly if it cuts out greedy for profit corporations.

It's soooo clearly the next step, I don't see rhyme nor reason in trying to sell something bigger. Hardly anyone would be against it, and it being a reality will educate folks-if they don't get it, someone they know will- about the actual costs, the upsides, the downsides, all the gory details about what's covered for how much, why certain things work better and other things don't, what might need to change, etc. Far better than a lecture from Bernie or a white paper will do. Obamacare did the same thing, everyone understands far more than they used to. Gradual transition is the only fucking way with this big a part of the economy, revolutionary upheaval is just not a winning campaign slogan with the political system we've got. On a national level, selling revolutionary upheaval actually draws away crucial voters that would hold their nose and vote for a little less revolution.