So Americans need those very systems and institutions pronto, stat, ASAP. But now there’s a very Big Problem. How are they to have them? Because the debt level’s already super high.

America is a sovereign currency issuing government. That means, simply put, that it can afford anything that is available and for sale in US dollars, which its Congress always has an infinite supply of. Its past spending and taxation levels might cause inflation if it gets too ambitious, but that is a "supply" problem, not a demand problem.

When Hillary mocked Bernie's agenda in the '16 primary she likened it to promising your kids a pony. Bernie's response should have been "We can give everyone a pony as long as there are sufficient numbers of them and the necessary support a pony would need in terms of feed, vet care, etc. Instead, he caved rather than give an economic lesson that would severely harm the donor class that his party depends upon as much as do Republicans.

It was a huuuuge opportunity lost, especially given that his chief economic advisor could have written the response in terms everyone could understand. Keeping the voting populace in the dark about federal financing and money creation is critical to keeping the working class subservient and preserving the illusion that the wealthy are "job creators", so the truth is going to be a tough sell. Your own misconception about the national debt is a good example of that, given that you are a trained economist with the best of intentions.