Except there's a difference between what we can reasonably expect the final law and costs to look like, and Sanders first proposal. If anyone thinks that the first democratic proposal is going to make it through Congress and get passed without changes, they haven't been paying attention to the Republican party for the last 20 years.

The current Republican stance on policy is basically to oppose anything the Democrats suggest. What this means is that it's impossible to propose reasonable legislation and get it passed. It either had to start out as an "opening offer" or it'll get watered down to nothing.

The simple truth is Americans spend more than anyone else for worse outcomes, and we generate a huge amount of profit for insurance companies doing it. There's almost no way we could come up with a single payer system that costs more. If everyone just sent their current insurance premiums to the government instead, we'd end up with a huge surplus.

Sander's plan raises less revenue than that, and offers more, but after making a few obvious concessions to Republicans we could still end up with a "Medicare for all plan" that would be a big improvement over what we have now.