When it comes to problems, there usually are no shortages. Therefore, the challenge will be to narrow down your topic to something that interests you. In light of this, let me give you a few examples.
First, if you have been following the news, there is a big problem with the IRS. They have been targeting conservative groups and making it harder for them from a financial point of view. This shows something bigger. We, as Americans, are becoming more polarized. Think of the Tea Party and what they are doing.
Second, another issue is the economy. In what meaningful way can we speak of the economy doing better, when we have printed so much cash? Moreover, how can we speak of a better economy, when the rich get richers, unions get weaker, and the middle class is pinched?
Third, think about the issue of drones. Should we use them? Are will killing innocent lives? War in general is a very large issue in any administration.