Name: Rand Paul

Previous Experience: Rand Paul was an ophthalmologist in Kentucky for 18 years before being elected to the U.S. Senate in 2010.

Signature Issue: Taking down big government. Paul has been most outspoken against government overreach in Washington. He often criticizes both parties for depriving Americans of their civil liberties.

Opportunities: His ideology in unusual enough to appeal to voters across the political spectrum, and he will claim that be can both help the party grow and safeguard conservatism. Having a diverse coalition may not be a bad thing with a field so large and split.

Challenges: He has flip-flopped on key foreign policy issues and then blamed the inconsistencies on the media. He also has a temper, as seen in the first debate when he battled with Trump, which could hinder him in a long campaign season. He might be trying to be too many things to too many different people.

Did You Know? In his free time Rand Paul travels across Kentucky giving eye surgeries to patients for free. He has also traveled around the world to perform surgeries, most recently to Guatemala on a medical mission trip.