Is the national anthem really just for Americans?

I recently read this post on upworthiest (which, by the way, I just discovered through my mom and others) about a young man who got grief because he sang the national anthem. Evidently, people who are not citizens have no right to sing the national anthem at a public event.

http://www.upworthy.com/some-racist-bullies-picked-a-fight-with-an-11-year-old-kid-and-lost-in-glorious-patriotic-splendor

First, let me say that he did a phenomenal job on a song that is extremely difficult, and one that many who have never been questioned about their legality and heritage have completely botched.

This young man is a born and raised American who honored both our country and his heritage by singing the anthem dressed in mariachi costume. Following the event, however, tweeters quickly posted racist comments about a Mexican singing the national anthem, to which he very eloquently replied that he was an American born and raised - and a fan of the San Antonion Spurs no less.

End of story for most, and job well-done by a courageous young man standing up to racist bullies. But it made me wonder whether there is still an underlying biased assumption underneath this argument. Do non-citizens have no right to be proud of this country in which they live? Do those who attend our schools, or work hard to put food on their table, whether legal or not, or visit the US to see all that it has to offer have no right to express their appreciation for our country, flaws and all?

It seems to me that focusing on the answer that he is, in fact, an American and so considering the issue closed skirts the deeper issue of racism and nationalism in our country today. If you think through the words, it expresses admiration for our flag, which in turn symbolizes the perseverance that all of our families have gone through to live here, whether we have been here since the beginning, or arrived just the other day. The fact is that we are a country of immigrants, some who came here when rules were in place, some who came when we made up our own rules, some who came here because they were lucky and some who came here just to have a taste of what life here might be like. We are all, in some ways, like the woman who reaches out to touch just the hem of Jesus' robe to cure her bleeding. Or the woman who begs for the crumbs that would otherwise feed the dogs so that her children may eat.

Doesn't that give all of us the right to sing the national anthem, and not have to prove to the world that we are citizens in order to do so?