Birth Date: June 17, 1943 (age 68)

Birthplace: Harrisburg, Pennsylvania

Accomplishments: Gingrich represented Georgia in the U.S. House of Representatives from 1979 to 1999. From 1995 to 1999, he served as the Speaker of the House, a top position. From 1989 to 1995, he served as the House minority whip, another important job. Before entering politics, Gingrich was a college history and geography professor. He is the author of 23 books. Gingrich is married to Callista. He has two daughters and two grandchildren.

In His Words: “My basic message is simple: If you want jobs and economic growth, I know how to do it,” he told supporters in Iowa. “I’ve done it twice before.”

Birth Date: August 20, 1935 (age 76)

Birthplace: Pittsburgh, Pennsylvania

Accomplishments: Paul served in the U.S. House of Representatives, representing Texas, in the late 1970s and early 1980s, and has served again from 1997 till today. Paul is also a doctor. He was a flight surgeon in the U.S. Air Force in the 1960s. Paul has campaigned to be President twice before, and has written several books. He and his wife, Carol, have five children and 18 grandchildren.

In His Words: “The most valuable resource for children, teenagers, college kids and adults is liberty,” Paul said in Iowa. “If we protect those liberties we will have the maximum amount of progress.”

Birth Date: March 12, 1947 (age 64)

Birthplace: Detroit, Michigan

Accomplishments: Romney has law and business degrees, and spent most of his career as a successful businessman. He helped organize and steer the 2002 Winter Olympics, in Salt Lake City, Utah. Romney served as governor of Massachusetts from 2003 to 2007, and worked to improve the state’s economy. He has written two books. Romney also tried for the Republican nomination in the last presidential election. He has been married to Ann since 1969. They have five sons and 16 grandchildren.

In His Words: “In the campaign to come, the American ideals of economic freedom and opportunity need a clear and unapologetic defense,” he told Iowa voters. “And I intend to make it, because I have lived it.”

Birth Date: May 10, 1958 (age 53)

Birthplace: Winchester, Virginia

Accomplishments: Santorum has law and business degrees. Pennsylvanians elected him to the U.S. House of Representatives in 1990. He served as a U.S. senator from 1995 to 2007. Santorum and his wife, Karen, have seven children. He is the author of the book It Takes a Family.

In His Words: “I’m going to do my best to strengthen the American family,” Santorum said in Iowa. “That’s how I’m going to strengthen the economy, how I’m going to strengthen America.”