Yes, I agree with that. I think Medicare for All kills two birds with one stone. It is an emotional appeal and a policy appeal. Democrats have only focused on the policy without the emotion for a long time.
Time to turn on old man mode: every generation of young activists in America has had to learn that working class people resist change. We think they should like it. Progress, justice, improving our lives, etc. It makes sense. But in my entire lifetime it has never been true. There are a lot of reasons for that, some good, some not so good, and I'll suggest a couple:
1. Loss of white male privilege. Duh.
2. Uncertainty creates fear. Lots of people have been talking about the difficulties of living paycheck to paycheck. Well, one of the realities is that you try to set up routines to help out. I live a block from my grocery store and I go to the store almost every day. Every Saturday morning there is one group of Latinas who buy like three carts full of groceries. I'm sure they are buying for several households for a whole week. I guess I shouldn't say every Saturday morning because I don't actually know that (I don't go every Saturday morning), but whenever I am there so are they, and I never see them elsewhere.
Change fucks it all up. When things change, you sometimes need to scrap those things that long worked for you. That's annoying. What's more, it's certain. Maybe the change will also carry benefits, but those don't always materialize. They aren't always easy to see when your focus is on next month. That was the political dynamic of Obamacare, and why it was so unpopular even as it was so good for many people.
Now, when things get bad enough, everyone can support change. And that's how Obamacare happened. Health insurance had become such a joke, such a fraud, such an impenetrable hassle that people said, "enough." They voted en masse for new health care.
But now that we have Obamacare, Medicare 4 All is not necessarily palatable. Most people have pretty good insurance now and they can get it if they want it. It's by no means perfect, but the delta from Obamacare to M4A is not that big. Probably not big enough to justify the inherent fear created by changing the whole system. This is why activists don't understand working-class reluctance to embrace causes that would seem to help them. It was certainly true for me and my activist friends.
3. Suspicion that change always screws the working man in the end. This is demonstrably not true, but it's widely felt. And it's a self-defeating message that is commonly broadcast by progressives. It's meant to galvanize solidarity, but the practical effect is to engender cynicism, and cynicism is a huge barrier to solidarity. The message of "the corporate overlords will never let you have nice things, so we need to take them like with M4A" can be heard as "the corporate overlords will never let you have nice things, and that will be true of M4A as well."