Its basic math. There is no way to pay for this.
You are correct, and it is the same story at a county, state and federal level. Our politicians have made promises that cannot be kept.
The real question is what happens when the people say sorry, we won't pay or when the money just flat runs out and does not exist. It is irrational to think that the people will be paupers to pay for public servants false beliefs in Santa Claus. As one looks at our future, this is the clear and until-recently-unspoken issue, how does a society deal with such irrationality?
Civil War, hyper-inflation, societal collapse or other are most likely. A mature attitude saying that we all knew it was impossible to get what is promised is unlikely IMHO.
This cannot end well.
schu