He made a terrible mistake, in that he took Republicans at their word, and thought that if he adopted the Republicans' positions
Bullshit.
You Democrats are revising history here. The people demanding the system that we got were the Democrats. They couldnt get enough Democrats to vote for single payer, so they started trading pages of legislation for votes. Thats Democrat votes, not Republican votes. The Democrats were exercising party cannibalism, blackmailing each other. Need I remind you that it both required zero Republican votes and also got zero Republican votes, so whose voters were they buying with this shit? Democrat votes, clearly and obviously. There is no other way to see it without being a disingenuous dishonest fuck.
And before you say "but it was just Romneycare" -- That was is Massachusetts, one of the most solidly Democrat State in the country. It just doesnt get any bluer. They did it to Massachusetts and then they did it to the whole country.