This is a way more difficult conversation to have with a reasonably informed person on the right than you are making it out to be...
The social security fund has been “borrowed from” to fund other programs.
The government is clearly in the pocket of big Parma.
The government uses taxpayer money to bail out Wall Street.
The government allocates subsidies based on lobbying groups.
The IRS specifically targeted right wing groups applying for non profit status.
The list goes on and on.
So people on the right are not keen to give that structure more money and power.
It doesn’t matter how successful you may think Medicare is. The power structure and track record of the entity which would manage universal healthcare is abysmal.
I think there is a way to do it which could make the whole program solid and resilient against abuse but the proposals all come from the left who don’t seem particularly interested in resiliency.