A prolific author, Paul has penned more than 10 books, including 鈥淔reedom Under Siege: The U.S. Constitution after 200 Years,鈥 鈥淎 Foreign Policy of Freedom,鈥 鈥End The Fed,鈥 鈥淭he Revolution: A Manifesto,鈥 and his most recent, 鈥淟iberty Defined: 50 Essential Issues That Affect Our Freedom.鈥

Richard Shiro / AP
Texas Congressman Ron Paul (R) speaks to a gathering of tea party supporters at the Hyatt Regency in Greenville, S.C., on May 5.