FWIW, to the extent that arguments are made that SoSec is not an entitlement, but a paid into owned benefit, then the same holds for unemployment benefits. This is a paid into system (insurance program) to theoretically provide benefits to those who suffer insured losses. In this case what is insured is employment, loss of employment being the insured loss. Now, when one wanders into the land of "extended benefits" then one wanders into the land of welfare. But just as SoSec is a paid into systems of retirement insurance, so to is unemployment a paid into system of employment insurance.
The broader question is the notion of means testing for paid into insurance systems. Certainly, if my house burns down, I am insured and I expect compensation, and I do not expect that my compensation is somehow means tested. I bought the damn insurance. That is where the anti-means testing wealthy perspective comes from, and it is by no means a a perspective on some sort of weak footing. The left has decided to have it both ways ... SoSec is an umimpeachable owned benefit because it was paid into ... well except for people who make more than we like. In which case they paid in and owned until we decided they are too rich and they don't.
The fair solution is to tax all SoSec, unemployment, and so on according to ones tax bracket. But these are paid for insurance programs, I can not see a rational way to exclude a segment of insurance policy holders from their coverage on insured matters.
As far as having the "well-off" pay more towards Medicare ... once again, the Medicare benefit should be part of box 1, wages tips and other income. If you are poor, it will be free, it you are rich, the benefit will be taxed at the highest marginal rate.
Coming up with multiple tiers of choosing to honor insurance obligations is a fools folly. These insurances (unemployment, sosec, medicare) should be treated as taxable income ... the progressive tax code will simply sort out who "deserves" more and who deserves less.