Once in a while, it's prudent to remember that the United States is an experiment. Like all experiments, it's outcome is uncertain and it's going to produce some anomalies and unforeseen outcomes from time to time. I think that's where we are at right now. We don't look the same as we did in our founding days, that's supposed to be part of the experiment. Can we design a system that is dynamic, that can be augmented to suit the times? America may not look the same in 8 years. But it hasn't look the same... ever. It's a work in progress.
I feel like the same could be said of all of humanity, and I think that's a good thing. We will screw up along the way, whether as individuals, countries or all humanity. Like you said, it's an ongoing experiment.