Of course the National Anthem is political speech. It is entirely political. The full lyrics can be found here:
The poem extolled the defense of Fort McHenry in the War of 1812. That was a war that we (the U.S.) started after a divided congressional vote which split along party lines. It was not a popular war at the time. The underlying issue was Britain's support of North American Indian rights in the face of American colonialism. Nowadays our history books mostly talk about the British press-gangs as being the impetus of the war, but this is itself a form of politics played by means of revisionist history. Bottom Line: the war was politically divisive, and the National Anthem supported the war.
Another political issue is the last couple of stanzas of the poem. Note the references to slaves and the rights of freemen. Frances Scott Key was a slaveholder and represented owners in cases to recover their runaway slaves. In fairness, he also manumitted some of his slaves, so he was not the worst of the worst. Still, songs supportive of the right to own slaves, written by slaveholders, are inherently political in a country that gave something like 600,000 lives fighting a war to end slavery.
In my opinion, our present National Anthem should be kicked to the curb, and supplanted by another. Aesthetically speaking, it is unsingable with tortured lyrical construction and such freakish octave changes that it can only be properly performed by shape-note singers. The melody comes from a British drinking ditty, and the lyrics are so obtuse that only about 40% of Americans know the words to the first stanza. And this is after hearing it thousands of times at athletic events. I doubt that even 1% of Americans know the entire poem; and really, who'd want to?
We have more popular songs that are much less politically repugnant. How about "This Land Is Your Land," by Woodie Guthrie?
This land is your land and this land is my land
From California to the New York island
From the redwood forest to the Gulf Stream waters
This land was made for you and me
As I went walking that ribbon of highway
I saw above me that endless skyway
Saw below me that golden valley
This land was made for you and me
I roamed and rambled and I've followed my footsteps
To the sparkling sands of her diamond deserts
All around me a voice was sounding
This land was made for you and me
When the sun come shining, then I was strolling
And the wheat fields waving and the dust clouds rolling
The voice was chanting as the fog was lifting
This land was made for you and me
This land is your land and this land is my land
From California to the New York island
From the redwood forest to the Gulf Stream waters
This land was made for you and me
When the sun come shining, then I was strolling
And the wheat fields waving and the dust clouds rolling
The voice come a-chanting and the fog was lifting
This land was made for you and me