At the risk of overstating the case, this is a form of propaganda. Kennedy was stating a position that is noble and which sounds good, but which is probably unmanageable. It is important that society find a way to help the poor, if only because it is necessary to have a strong middle class (created through helping the poor --- or which is at least an option held out to the poor) to protect the whole free society; people need to have the hope that they can move up to keep the society stable.
The problem I see with Kennedy's statement, which is clearly an idealistic position, is that I don't know what the "save the rich" means ... unless it refers to maintaining the hope of the poor to keep them from rebelling against the rich. But it seems unlikely that this revolution could happen in our country. And how much can we take from the rich before they're not rich any more? We are presently taxing the rich (which, by the way does NOT include me :)) ... is it possible to tax them so much that there's no more to take? Then what? And, of course, where does the right to tax people like this come from? Just as the poor need the middle class to aspire to, so the middle class needs the rich to aspire to.
I guess your reaction to Kennedy's statement depends in part on whether your favor a socialist or a free market system ... or a blend of the two --- which I think the US is now. The question is how much of which viewpoint goes into the blend?