The answer is: Both try to convince people to take action or accept a certain belief.
Political speeches often disseminate a certain belief or idea to its audience. Oftentimes, it is trying to persuade the listener to act upon what is being said. In the same manner, persuasive writing presents certain idea and it convinces people to act upon the idea presented.
You should start with listing the different ways you want to test them. Then each paragraph should talk about each different method and the results. Hope this helps.