The theme of the poem is basically the American Discrimination. Discrimination is basically is a term which is used to define the difference b/w two groups on the base of some qualities etc. For example the American Discrimination was between black and white people.
Hello his name,
I am very sorry but I am unable to join you for dinner tonight. However, I would still very much like to go to dinner with you. Would we be able to meet for dinner tomorrow?
Thank you,
Your name
Hopefully that’s not too formal haha