I've been hearing that since the eighties. Congress can change contribution rates and/or benefit rates at any time to keep it solvent, just like they have in the past.
Beyond a certain point, the working population will not be able to afford to pay for the retired population. It's a mathematical inevitability unless birth rates increase or people stop living as long any more (both probably impossible). Maybe the benefits could be eliminated/reduced, but this is politically untenable because older people generally vote while younger people don't.
immigration solves the birth rate problem, and is one of the big reasons why illegal immigrants is a hilariously terrible wag-the-dog wedge issue. make them legal, tax them, and have them contribute to the system as well.
