Understand the situation before you begin to dissect the speech. By knowing who the speaker is and what their background is in relation to what they're discussing, you'll be able to speed up the process in which you can determine why the speech is being given in the first place. For example, a speaker with a long history of defending civil rights will likely offer a different kind of speech than a young professor who has just studied the history of civil rights.
Read the content of the speech, if possible. Major political speeches often get transcribed and can be accessed through political websites or newspapers. Get a feel for what the speaker is saying and why. In other words, figure out what the intentions of the speaker seem to be.
Analyze the audience. Knowing about the audience can help you do an effective rhetorical analysis. For example, a speaker might be focusing far more on the safety of children in response to a desired curfew law than the safety of adults when addressing an audience of young mothers. If the speaker had been talking to college students, the entire approach of the speech would probably be different.
Watch the speech, if possible. The speaker's inflection, body movements and expressions might reveal more about his intentions and what parts of the speech are particularly important. Although many subtle parts of the speaker's body language may be hard to recognize, focus on whether or not the speaker's movements match up with the words being spoken, such as a forceful hand gesture accompanying a forceful phrase. The forceful phrase is a type of tone, just like sadness would be another type of tone. This can reveal a lot about the speaker and help you further analyze the content. Using the prior example, the speaker might have a tone that is meant to invoke fear when addressing young mothers but a passionate, angry tone that implies social injustice when addressing college students.
Pay attention to how the speaker organizes the speech. If the speaker starts off with a joke, for example, you can identify a different purpose than if he starts off with a sad story about an injustice. Some speeches might be organized in a way in which everything leads to one main idea or opinion, while other speeches might be organized in a way that jumps from one topic to another.
Discuss whether or not you believe the speaker did an effective job communicating the intended message to the particular audience being addressed. Use examples from the speech where relevant and make suggestions for how the speech could have been improved to make the message clearer or more effective for the specific audience being addressed.