“You find these in her letters, too. I think she just liked that form of punctuation. To me, there are dashes often between a subject and a verb. They’re kind of interruptive, strange dashes that don’t seem to do anything more than reveal her love of the dash, but then there are other dashes to me that are indications of a leap of thought. Whereas a comma or a semicolon doesn’t get the sudden transition as she’s moving from one word to another — so, a sort of zigzag type of logic. So, the tension in her poems — there’s a feeling of reliability about the meter, which is the common meter; there’s a kind of political vocabulary that’s going on, and then there’s a very radical and audacious and daring content and a completely original use of language.”

http://www.npr.org/templates/story/story.php?storyId=128272101