I think Germany itself is a perfect answer to your question. One thing you start to see over and over in politics is Newton's Third - for every action there's a

I think Germany itself is a perfect answer to your question. One thing you start to see over and over in politics is Newton's Third - for every action there's an equal but opposite reaction. Germany took an an overwhelmingly sharp anti-nationalist turn, and what happened? Now we see things like the AfD (far right/nationalist party for those unaware) going from a niche little party that couldn't even qualify for the electoral threshold to the second most popular party in the nation, the #1 in east Germany. And similar things have been happening throughout Europe. People being unified within a nation is a very good thing. And being unified does not mean believing the same thing. There have always been extremely divisive politics in the US. You only need look at our money - the man on the $10 bill was killed by the vice president of the man on the nickel in a duel. But when people start to become mutually exclusive, or when a nation itself goes too far in one direction, or the other, it results in a sharp counter movement in the opposite direction. It's important that people ultimately view themselves as part of a whole, even if they might strongly disagree with one another. A flag is the most fundamental representation of that whole. The alternative tends to trend towards widescale conflict which rarely has a happy ending for anybody.