Allen Ginsberg - Poetry

From what I can recall, Allen Ginsberg was an important 'beat' poet.  Not that I really know what that is, but I've at least heard of him.  This poem is 'A Supermarket in California' and I don't think that I know it.  But of course I soon will!

What thoughts I have of you tonight, Walt Whitman, for I
walked down the sidestreets under the trees with a
headache self-conscious looking at the full moon.
In my hungry fatigue, and shopping for images, I went
into the neon fruit supermarket, dreaming of your
enumerations!
What peaches and what penumbras! Whole families
shopping at night! Aisles full of husbands! Wives in the
avocados, babies in the tomatoes! - and you, Garcia Lorca,
what were you doing in the watermelons?

I saw you, Walt Whitman, childless, lonely old grubber,
poking among the meats in the refrigerator and eye the
grocery boys.
I heard you asking questions of each: Who killed the pork
chops? What price bananas? Are you my Angel?
I wandered in and out of the brilliant stacks of cans
following you, and followed in my imagination by the store
detective.
We strode down the open corridors together in our solitary
fancy tasting artichokes, possessing every frozen delicacy,
and never passing the cashier.

Where are we going, Walt Whitman? The doors close in an
hour. Which way does your beard point tonight?
(I touch your book and dream of our odyssey in the
supermarket and feel absurd.)
Will we walk all night through solitary streets? The trees
add shade to shade, lights out in the houses, we'll both be
lonely.

Will we stroll dreaming of the lost America of lost past
blue automobiles in driveways, home to our silent cottage?
Ah, dear father, graybeard, lonely old courage-teacher,
what America did you have when Charon quit poling his
ferry and you got out on a smoking bank and stood
watching the boat disappear on the black waters of Lethe?

My first thought is that there is probably ton of references in here that I'm not getting.  My experience with Whitman is very limited, especially to his biographical details.  I read that he's childless and eye[ing] the grocery boys.  Does this mean that he was maybe going to pick one of them up?  And who is the Angel that he was seeking?  I don't know and I suspect that this means I miss out on a lot here.
But put that aside.  The idea of the poem is certainly interesting.  If I was out late at a grocery store and I tried to have a conversation with a literary idol, how would that go?  I think I'd discuss ideas, but that's what attracts me.  This conversation is driven entirely by feelings.  Ginsberg and Whitman are lonely and wistful.  They search for something that isn't there and probably never was.
Ginsberg seems to suspect that in the final stanza.  He asks Whitman 'what America did you have' when he died and went to Hades.  A different one in many ways but still the same in others.  Does Ginsberg feel a betrayal at (his) modern America, especially in comparison to Whitmans?  Probably.
Hmmm.  It doesn't really speak to me but I respect it.  Maybe Ginsberg and I are just in different keys.