The common denominator is collectivist philosophies. From Paul Rosenberg at freemansperspective.com:
Once upon a time there really was an American exceptionalism and America was a light unto the world. That exceptionalism was a long way from perfect (looking for perfection in a mass of humans is silly), but it was legitimate.
Alas, that was long ago. People who say that American exceptionalism still exists may not have bad intentions, but they don’t understand what it was. Others, with less noble intentions, promote the idea to whip up support. Telling people to praise themselves is always a big seller.
Exceptional Means “Not Like the Others”
A Bible passage that has always stuck in my mind is I Samuel, Chapter 8. In it, the Israelites, then living in a tribal anarchy, go to Samuel the prophet and tell him to appoint a king for them. Samuel warns them profusely not to ask this (“Your king will take your children away, take your crops, you’ll cry out for relief,” and so on), but they wouldn’t listen. “No!” they said, “We will have a king over us and be like the other nations.”
In other words, they threw away their exceptionalism and became like everyone else.