This type of speech will require in-depth research. Magazine and newspaper articles provide an overview of your topic and will lead you to more detailed information. Statistics will provide support to your arguments and convincing evidence. You will be able to argue specific sides of your issue without sounding vague or speculative.
Here are some helpful questions to ask yourself,
Review this list of topics for your persuasive speech
Google Scholar searches scholarly literature and includes peer-reviewed papers, dissertations, book citations, preprints, abstracts and technical reports from a variety of content providers. Sources of material include academic publishers, professional societies, preprint repositories, universities and open access publishers. Some content is available in full text.
If the library has a subscription to the electronic version for the journal, you should have access to the article. Use Interlibrary Loan to request articles that you are not able to access online.
Statistics are everywhere. Data and statistics are reported in newspaper and magazine articles, announced and reported in scholarly articles and government reports. To insure the reliability of the data you should consider following.
Always cite the source of the data in your speech. Providing the source will provide credibility for you and will strengthen the impact.
Limit your statistics. Too much data can be confusing and tiresome.