I think that, at least that "perfect union" part of the quote, is self-aggrandizing blather.

Hmmm, it's kind of meaningless to say it is one's duty to love something. Either the emotions are engaged or they are not, and it has little to do with what we ought to do.

Other niggles.

So, bottom line for me is, though I approve the sentiment, I feel that it cries out for a rewrite.

On the other hand, I appreciate that you are looking for heartfelt declarations of support from the good guys; and for evasions from the unworthy. So I will say, this maudlin creed aside, I am very fond of America. I think the Constitution and the Bill of Rights are amazing and wonderful documents. They are certainly worthy of the spilling of my blood in their defence.

[Though it seems to me that they need defence more from my fellow citizens than from any external threat.]