To be fair, Sanders has written up a possible (though very ambitious plan) on how to enact Medicare for All. I believe Clinton while not as ambitious may have wanted to bolster Obamacare which did seem to reduce the numbers of some insured (with your point on the coverage shifting standing). That said, I could understand why you could be skeptical of those plans (ACA didn’t cause universal insurance in the first instance even if numbers did fall and taxes are a political football).
In all the talk about universal healthcare, I have never seen a serious explanation of how that would work, what it would cost and how it would be paid for.
Some ideas I know would including possibly ending the tax-exclusion on medical care and/or employer-sponsored heath insurance plans which delink the need of health insurance from work in favor of a public system while shoring up possible revenue sources to pay for public coverage. Additionally, we would also match the FICA tax rate with the payroll tax rate to help pay for a baseline or floor of universal coverage/care though I know this would have substantial circumstances (while being significantly unpopular and considered quite regressive). Meanwhile this could be augmented by providing a surcharge on the incomes of the upper middle class and wealthy. Finally sin taxes while small could also help.
Granted it may just be cheaper and simpler to create a stopgap and try to enroll all the uninsured into Medicaid for some barebones plan while trying to fund for that (i.e calculate the average medicaid costs per person and use that to fund another medicaid expansion). That said, I know that could incentivize some employers especially at the margins to consider dropping their workers since there is now a fall-back but perhaps when that is happening, people can begin debating on shifting towards a universal plan.
Never have I seen a proposal that deals with illegal immigrants, of whom there are what, some 20 million now?
If they paid into the FICA tax and possibly income taxes, wouldn’t they already be helping fund the system. Additionally, couldn’t one argue that although they are here illegally, illegal immigrants have as much a right to health care on humanitarian grounds as well as practical issues like public health concerns (if they stay underground and go without care, it could jeopardize public health).
Who’s going to administer it? The same insurance companies that administer government programs now?
In this respect, I could see one cost or trade off of the universal plan being the quality meaning those on premium plans might end up opting for a medicaid-style plan with some inconvenience like waiting lists but for others, particularly let’s say a desperate soul with little to no options (think working class folks who are barely making it paycheck to paycheck), it’s some sort of recourse. Additionally, some may prefer to deal with government or have government take care of it rather than have the hassle of working with insurance while others may see it as simply trading in insurance premiums and deductibles for a moderate rise in taxes and hopefully less anxiety.