Think of the past three days. What you did, where you did, and with whom it was done. In the current world, is there a nation where those three days of activity and experience would have been better?
Unlikely. For any person with some intelligence and some motivation, the current United States is the regime most friendly to flowering the human potential. And that’s what we’re supposed to be waving flags about today. U.S.A.! U.S.A! U.S.A.!
Some faction will use their liberty to dwell on the persistent injustices that come when fallen man is given his measure of freedom. The cheerleaders will counter with all the instances where the United States (or the States themselves) have corrected injustice. Or at least the institutional expression thereof.
In the top tier there, slavery is ended. And black culture is probably the single largest influence on the broad American culture. Some peoples have come a long way.