The challenge is to redesign the program to be sustainable. That means a light touch of welfare for those who are unable to contribute much. (that way the pressure to add benefits later is reduced) The current system penalizes the poor and unhealthy, while benefitting the reverse. This could be addressed by adding inheritability. Make FICA more like an IRA that can benefit the children of rich and poor, not just the rich healthy cohort at the expense of the reverse.
The welfare aspect establishes a basic floor for benefits at poverty level and not much more. It can be paid for with a ceiling for benefits, since those that do quite well will not rely on FICA anyway.
The vast majority of folks between the floor and ceiling get a sliding benefit proportional to contributions.
This transforms FICA from a wealth transfer political program into a wealth building program, much like IRA/401k plans are today. The third rail of american politics can be removed, forever. Politicians would lose the ability to manipulate benefits or taxes to buy votes. Or quietly fund the military industrial complex.
And this would eliminate the intergenerational warfare that characterizes FICA discussion, current voters vs the unborn or not yet voting.
And then there is the problem ShokWavRider mentions: We have to operate on the patient without killing them. Agreeing on a destination for FICA is one big problem. Agreeing on how to migrate from our current insolvent mess is a very hard problem.
Alternatives: ignore it and print 200 Terabucks to paper over the entitlement program insolvencies and watch Rome burn. Wait for angry young voters to out vote the retirees and push them aside... and watch Rome burn.
This is a hard problem to solve. Chile and Switzerland and about a dozen other nations have had successful reforms. It takes decades to complete the transition.
I much prefer legislative sausage via a functioning congress. Lacking that, the pirates will run the blockades, as will the rest of the world, building inexorable force for change or poverty. I fear the monetary destruction required to pay for the current system will do what the war on communism did, kill the villagers to save them.
The Kennedy clan were pirates of prohibition. Many pirates are executed, some are exalted.
I like the Gimli quote here from LOTR: "Certainty of death. Small chance of success. Well, what are we waiting for?"