Simple - the payroll tax doesn't raise enough funds to cover the full cost of the program. Even if it did raise 100% of the needed funds, that's still money Congress cannot tax a second time. At the end of the day, the government has two buckets: income and expenses. It doesn't matter whether some of that income is called "payroll tax", and some of it is called "income tax". Every cent raised through a payroll tax, is a cent that cannot be raised through an income tax, and visa-versa.

>Replace Medicare and Medicaid with a socialised 1 payer system as it would be much cheaper.

Yet...none of the advocates of a socialized healthcare system have ever put forward a real bill that can be rated by the Congressional Budget Office. Instead, they put forward shell bills which importantly lack any funding mechanisms.

> The numbers I saw was that the current system costs 48t and 1 payer system would be 32t.

The current system is divided between public and private spending. Even if you could reduce the overall cost to 32T, that's still a net cost increase on the public side. How will the government raise that money? The advocates for social healthcare never say.