Why are we opposed to partial-privitization of Soc. Security? [View All]

I understand the argument about the transitional costs. They are astronomical. But beyond that, why do we as Democrats oppose it...in principle I mean? Correct me if I'm mistaken on this. I'll admit, I've only recently started taking interest in this debate.

From what I gather, people are only able to take a portion of their Social Security taxes and invest them in these private accounts. The rest would continue to go into the system as it currently does. Also, these accounts, over time are likely to grow a lot faster than money in SS currently does, even in very conservative investments, making SS provide better than it currently does. And no one will be forced to switch to this kind of account if they don't want to.

So help me understand what (besides the transitional costs argument, which I agree is a big problem) is the reasoning behind opposing any effort to change SS as it currently exists to have any element of privatization.