Those bastards in their mansions:
to hear them shriek, you'd think
I'd poisoned the dogs and vaulted the ditches,
crossed the lawns in stocking feet and threadbare britches,
The opening line is stark in its statement of hatred, so that the reader is pulled in immediately. The abrupt beginning launches the reader the into the middle of a conversation, a technique known as  in medias res . This is clearly a poor man who resents the rich. The language is colloquial and spare.
Those Bastards in Their Mansions