Social Security is no different then any other Ponzi scheme. As long as more people pay in instead of taking out everything looks great. Eventually the day comes when there is not enough new people giving money to keep the scheme going.
This is a scary thought, but Social Security should be scrapped and replaced by 100% voluntary private accounts. People will lose money and be hurt. Better to have the hurt come quickly like ripping off a bandaid then letting the agony go on for years.
Republicans and Democrats are equally to blame. To say that Social Security can be saved is like saying you can eat ice cream every day and not get fat. Everyone wants to believe it, but it can't be done.