What could the concentration of wealth mean over the long term?

I'm trying to internalize what a society might look like in which the upper one percent controls as much wealth as the bottom 50% -- an unprecedented circumstance that has taken form in the last few years in the United States. I ask this because a transition like this, on such a scale, has to have long term implications. As affairs progress we will come to see how much has changed while we supposed that everything had stayed the same.

So, what can be done with such huge advantages in the control of wealth? Consider today's news.

At this moment we see that Qaddafi has been able to recruit hundreds [thousands?] of "fighters" on behalf of his "Libya" simply with what is said to be a great hoard of cash inside the country, even though whatever he claims outside of the country has been impounded. [NYTimes Mar 10, 2011] That is, you can buy people to help you fight your battles if you have enough cash around.

For another, Qaddafi can terrorize and torture his own people -- and even BBC reporters -- in order to control information. One of his fighters was wounded, we learn, and he has been cared for by the opposition. He asked where the Americans were: he had no idea that he was not fighting Americans, as Qaddafi has claimed, but his own people. So, as another example of what can be done by those who have the wealth in hand: you can establish mechanisms for controlling information, some of them brutal.

For another, if you handle enough cash you can hand over bundles of cash and pay off all the involved figures in the transaction, in order to support your election bid, or establish an escape villa in the Gulf. This at least is what Dexter Filkins tells us is happening in Afghanistan. [New Yorker Feb 14-21 "Letter from Kabul: The Afghan Bank Heist."]

Could it happen in America? We tell ourselves it could never happen here. But our system was originally founded on the separation of powers. Now that money is so concentrated in the hands of so few, how effectively will the separations of powers work? Could the same interests be on both sides of a transaction? Could they control all three of the main institutions of government?

Questions worth asking.