"The Wut-Wringing Machine" from Erections, Ejaculations, Exhibitions and ...briefly talks about the Vietnam war and how "too many people depend and profit" on it. And he talks about politics, including the Cuban crisis, Vietnam and "lost H-bombs" in "Politics is Like Trying to Screw a Cat in the Ass" from the same book.
In the letter-collections he mentions hating Nixons face in several places, saying, it's a "face of power" and it's troubling him for a long time because he has worked for faces like this all over the country (not verbatim).
This was before Watergate and could be considered somewhat prophetic, but then, once said: Nixon really had a kind of evil face, or does it just seem like that, knowing the history?
For someone who was very prolific during times of great change in America, he wrote very little about politics or the broader culture. His letters may mention politics and current events more often than his poems.
I remember the Los Angeles times asked him for a comment about the riots in 1992 and they printed his reply, which was basically, "Thanks, but no thanks" Ha.
Maybe he saw too many other artists persecuted for their political positions?
Or maybe he saw politics as a moving target and preferred to stay loose.
I believe he mentions something like the later at some point.
Also - he was probably aware of how writing can seem horribly dated when it covers 'current' events.
I think he was aware that he was writing for posterity and didn't want to include to many political views or pop culture references.
Most of his work has a definite timeless quality to it, I feel.