The Democratic party on a national level is to the left of where a lot of these people were, so any D president (could've been Hillary, could've been Biden, whoever) was going to require them to either break with their party leadership or take some votes that were going to cost them in their home district. Even if they would have taken Rahm's advice and scaled back the ACA to basically a slightly expanded SCHIP program, it still would've cost them because it was a mostly untenable alliance between a more progressive party whose legislators were coming from largely more conservative districts.

It's not really feasible right today to put together a Blue Dog coalition made up of legislators from R+ districts and enact any sort of genuinely progressive legislation. Fortunately, the current Dem caucus in the house seems pretty united (though once we're at the part where passing legislation that the President will actually sign happens, we may see some divisions.) But I doubt it will be anything as bad as Lieberman, Ben Nelson and Mary Landrieu holding the ACA hostage every other week.