Social security is not an unfunded liability. If you look at your paycheck you will see a line that explicitly goes toward funding social security. It is currently underfunded due to (1) Congressional malfeasance; and (2) the $120K cap on paying into the fund.
Even the underfunding is nowhere near as bad as advertised - current funding is sufficient to pay full benefits through 2035 and about 80% of benefits from 2035-2094. If we pay back the borrowed money and remove the income cap the funding issue would resolve.
It is only underfunded due to these two reasons.
Well, which is it? If it were simple to make social security solvent at full promised benefits then surely we would?
And no, surely we wouldn't. The Republican Party wants to destroy Social Security, they aren't interested in anything that would make it stronger.
What we should actually be doing is pay as you go. You pay into the pension and you get out what you paid, plus growth. We could have switched to this model at any point over the last 70 years if American society wasn't so addicted to endlessly kicking shit down the road and punting on problems.