Mandela moment? Nope, sorry to disappoint you. The 2008 US Elections may well be the most significant elections yet… but the fact remains that it just doesn't matter who warms the President's chair in the White House. Bush's 8 years in office have certainly not been America's finest hour; but would things really have been different if the Democrats won the elections? Well, in fact, they might have been; but the problem here is that the framing is all wrong. The President is just the tail of the dog, and the dog does the wagging, not the tail. The problems currently facing the USA come from the ground up, and not the top down.
The "Mandela moment" in South Africa was not important because of Nelson Mandela. This does not diminish Mandela's contribution to the country's renaissance in any way, but the fact remains that Mandela is largely symbolic of the turning of an era, a widespread socio-political change that, once again, came from the ground up. Mandela was merely the acrobat at the top of the pyramid.
The Obama campaign may have focused on the "real issues" far more than McCain's platform; unfortunately, in many cases, there is just lip service and handwaving as to how these issues are to be addressed, but really, that's just how the political game is played. Either way, it just doesn't matter in the end; regardless of how badly Obama wants to make things change, he just doesn't have that kind of power. He's going wherever the base of the pyramid takes him, and that's all there is to it. The irony is that he will most likely be remembered for how well or how badly the USA weathers the coming economic storm, but it's unlikely his efforts will have much influence on the situation one way or another.
Still, couldn't Obama be representative of the changing situation on the ground? In order for that to be true, his victory would have to stem somehow from that change, but the reality is that Obama won the election primarily through votes from those who would not have otherwise voted. There's no sudden change of heart here, just the relentless progression of time, as the newer generation replaces the older generation; a process that has been well underway for a long time now. The fact that he managed to rope in new voters is, perhaps, interesting in and of itself, but isn't likely to have any influence beyond the sphere of electioneering.