A huge part of the controversy about "pure" Medicare for All is tied to the fact that nearly 50% of the population (roughly ~160 million Americans, give or take) currently receives healthcare coverage via their employer. Some of this Employer-Sponsord Insurance (ESI) is pretty damned good, while some of it kind of sucks, but that's how our absurd system currently works for good or bad.
Anyway, most employers cover the bulk of the premiums for their enrollees...but a lot of people (my guess is the vast majority) either have no clue that they do so or at best have no idea how much of their monthly premiums are covered for them by the employer.
