Wearing a shirt color you happen to like is genuinely important because it will help your football team win. Supporting a law you happen to like will help your country win. Justification. If it precipitates actions that promote the overall well-being of others, I don't see a problem, even if it strikes me as about as "real" as typology. If its used as an excuse to be cruel to people who happen to be excluded from the group, I think there's gotta be bullshit to fall back on that's more logical at face value to support the assholery than "Go Vikings." (I'm American and I think that probably influences my answer, so I identify with my country in that sense. I also think that things that are good for Americans in general will probably affect me, which I think is nationalistic in a literal sense, even if I don't use it to bolster specific ideas, so it's not nationalistic in the sense it usually means.)