Expose yourself to multiple works. Try reading a few of Davis Hanson's pieces on foreign policy or education. His website is host to archives of every genre that he approaches, so take time to navigate and browse topics. By exposing yourself to a variety of his works, you will find what interests you the most. Focus on what interests you to ensure that you will be enthusiastic about your research.
Look at his new commentary section. This is located on the homepage of the Private Papers website. This page is host to recent posts and thoughts. Compare the new posts with the old posts to see how his opinions and thoughts have changed or matured over the years. Use this as a writing prompt if you are looking for a quality research topic.
Compare Davis Hanson's writing styles between types of published works. It's possible that you will see a more relaxed style within his social commentary, as compared to his documented works on military history. Explore the differences between the styles and explore why he might choose different methods between projects. Correlate the writing styles with the corresponding subject matter.
Use some of Davis Hanson's new commentary section and formulate your own arguments. Either add on to the elements that he has created or play "devil's advocate" for the opposing view. This may help you research as you will find out how you really feel about the topic, instead of merely digesting the information presented to you. Group several pieces together and use them to form a new topic.