I've found it more beneficial to "dumb down" persuasive papers. Making them too wordy or using too complex of words loses the reader's interest. Think of it this way; if someone starts reading your essay, there are no forces involved to make sure they keep reading your essay. A reader is constantly looking for an excuse to stop reading and move on. As the writer, it's your job to keep their interest. Granted, in order to make your points you will have to explain scientifically how cannabis works, but you need to make sure that after every wordy or sciency factoid you throw in there you are rewording it in layman's terms. Less is more. An easy to read essay always does better than a cluttered and wordy essay.