History repeats itself

I believe in the cyclical view of history, in which civilizations rise and fall periodically. I have read that there are many parallels between the American Experiment and the Roman Empire. We may have yet to reach the peak of our power, but Rome was at its peak around the 200 year mark and was destroyed inwardly by moral decadence, which made it vulnerable to overthrow by the barbarians from the north. Our moral decay is evidenced by the Massachusetts "marriages" and our barbarians are from the Middle East.