Kline received his J.D. from the University of Kansas School of Law in 1987, and was an Associate Editor for the "Kansas Law Review". He entered private practice as an associate with Blackwell Sanders, a large firm in Kansas City specializing in corporate law. He married his wife, Deborah, in 1989, and settled in Shawnee close to where he grew up. The Klines have one daughter, Hillary, born in 1992. They are members of the Central Church of the Nazarene in Lenexa, Kansas.