Irrespective of your political persuasion I encourage you to watch Michelle Obama's speech at the Democratic National Convention.
In particular I encourage you to note her use of story and metaphor to carry her message. I don't know whether she had support in constructing her speech (it is unlikely that she didn't have help) but on many levels that doesn't matter, it is her delivery that I encourage you to view.
Story and metaphor are extremely powerful in terms of conveying messages. Consider the fact that Michelle doesn't use any props throughout her speech. The entire 25 minutes is simply her constructed from her voice and using the power of tone, scanning, metaphor and story to carry her messages.