Ginsberg

The way in which Ginsberg lists what the kind of people he sees is relate able to Whtiman. He is bringing attention to these people who might otherwise be overlooked,
"angelheaded hipsters burning for the ancient"
Ginsberg includes America in his poetry as Whitman does, 

"who thought they were only mad when Baltimore gleamed in supernatural 
  ecstasy,
who jumped in limousines with the Chinaman of Oklahoma on the impulse 
  of winter midnight streetlight smalltown rain, 

who lounged hungry and lonesome through Houston seeking jazz or sex"


A super market in California,
Just the title reminds me of Whtiman, in it's simplistic, very "American-like" sense, just a super market in California but it holds such significance to the country and what it means to Ginsberg. 
And to point out the obvious that he addresses Whtiman in this poem is very clear that Whitman has influenced him greatly.
It's difficult for me to decide whether Ginsberg is questioning Walt's way of looking at things or if he is glorifying him. 
This part in particular suggests maybe that Ginsberg never knows where Walt is going with his poetry and the questions he poses,

  "Where are we going, Walt Whitman?  The doors close in
an hour.  Which way does your beard point tonight?"

Or maybe be is trying to see the way Whitman saw things, Walt saw America in such a positive light, with hopefulness and ability where as Ginsberg seems a bit put down at the current state of the country. Ginsberg suggests that Walt would be confused and ask a lot of questions, 

 "I saw you, Walt Whitman, childless, lonely old grubber,
poking among the meats in the refrigerator and eyeing the grocery
boys.
          I heard you asking questions of each: Who killed the
pork chops?  What price bananas?  Are you my Angel?"