wiki wacko says:
"A
rhetorical question is a
figure of speech in the form of a
question posed for its persuasive effect without the expectation of a reply (ex: "Why me, Lord?")
[1] Rhetorical questions encourage the listener to reflect on what the implied answer to the question must be. When a speaker states,
"How much longer must our people endure this injustice?", no formal answer is expected. Rather, it is a device used by the speaker to assert or deny something."