Horrific to some maybe. This was my five year old's automatic response to the national anthem coming on TV around last Christmas. Dude dropped his matchbox cars and everything to stand up and place his hand over his heart. I was going to put this in the political whining forum, but no whining here, just proud.
You're obviously raising a young adult rather than a lifelong child. Good reflection on this guy's parents. Be proud!
Good on your son. I'm wondering, does the school he goes to still do the Pledge of Allegiance? My second grade daughter says it every day in school. I was surprised because I figured the Pledge was a thing of the past, but when she came home from kindergarten one day repeating some of the words, I questioned her and found out that it was still a priority in her (public) school.