[tophat9000]

He called a friend and headed straight to the Red and Black Cafe, an all-organic, wheat-free, vegetarian coffee and food shop,

All right some one clue me in on this one...what is there issue with wheat?

[Californiajones]

It's pretty funny considering the context: lots of urbanites consider themselves "allergic" to wheat. As in bread or anyplace wheat might lurk. (Their overpriced "nutritionalists" have diagnosed them this way.)
Humor in that the red states are where wheat is mostly produced!