My husband and I have gone back and forth on this issue. I am the immigrant, the one born in Wales. He's the 21 year AF veteran (I'm also a British Army veteran) - before I became a US citizen, my remit during the US anthem was to stand respectfully (no need to place hand over heart), people kneeling during the anthem are doing so (my opinion), respectfully. They are not shouting, goofing around, dancing - the two guys behind us last night's game with their arm raised (in the Black Panther salute) were doing so very respectfully - that was a powerful statement ... Do you know I feel it equally disrespectful of the FedEx field crowd when they shout "O" during the anthem. It's all about respect to your country and your flag!
And again ... I was born and raised in Wales - at sporting functions our National Anthem is sung by the crowd (and always done with a passion) ... And man, what a feeling that is - I'm not sure how I would feel if a Welsh player kneeled. I really don't.