How is social security in the US at risk of running out of funding, if every tax payer pays into it?

Question

How is social security in the US at risk of running out of funding, if every tax payer pays into it?

In: 1004

Answer 1

withdrawal > deposit = -ve balance = runs out

but, that is not how stuff works, in terms of US at least, it is moneterily soveriegn nation.