One way to start is to look for recent articles about the political issue and the political system you have chosen to examine.
Using the database Academic Search Premier, here is a sample of what a search might look like:
Browse through the results for some very general ideas. What issues are rising to the top? What interests you?
Another way to start is using CQ Researcher. Each report gives thorough coverage of issues that are facing American society, including background, debates and controversies, trends and future scenarios. Search it by topic.
Each report will include the sections shown below, helping you to get a good grasp of the topic so you can look for further research. Note names of bills, laws, movements, important people, and events to use when looking for your scholarly articles.