Why is it so hard to cut Social Security when most young people don't believe it will survive?

Why is there so much support for Social Security when polls say most young people don’t believe it will be there for them when they reach retirement? It seems to me that if people are fatalistic about this, and they think Social Security will be worthless, then there wouldn’t be any point in trying to keep it funded.

Everyone knows that Social Security is underfunded. I’m sure most people are very pessimistic about the chance of any realistic way to support it. Yet it seems like it is impossible to attack it, either. Fiscal conservatives talk a good line, but it seems like they don’t have to worry about putting their money where their mouths are. Legislation to make significant cuts in Social Security seems to have little chance of passage.