Kline was a polarizing figure in state politics, largely surrounding his use of his office to investigate abortion providers. He filed charges against George Tiller, a late-term abortion provider, and led a years-long effort to prosecute Planned Parenthood in Kansas. Kline received a series of official rebukes and reprimands for his legal tactics against abortion providers, and in 2013 his law license was indefinitely suspended by the Kansas Supreme Court, which found "clear and convincing evidence" that Kline committed numerous violations of conduct rules, which included providing false testimony. Kline appealed his license suspension to the U.S. Supreme Court, which declined to intervene, leaving the suspension in place. Kline is currently an assistant professor at Liberty University, an evangelical fundamentalist college in Lynchburg, Virginia.