Einsenhauer is a Kansas native who attended Emporia State University. After completing his undergraduate studies, he entered the US Army, serving a tour of duty in Vietnam. He then entered Drake Law University Law School and went on to practice law privately for 11 years. From 1985 to 1993, Eisenhauer served as a juvenile referee and in 1994 he was named to the district court bench, where he remained until 2001 when he was appointed to the Iowa Court of Appeals. He remained on the court in both 2002 and 2008 through voter approval.
In the past he served as a faculty member of the Iowa Child Abuse Academy and a member of the Iowa State Bar Association Family Law Committee. He was the chair of the Supreme Court Advisory Committee on Court Appointed Special Advocates, chair of the Supreme Court Advisory Committee on Juvenile Court Officers, and an Advisory Board member of the Criminal and Juvenile Justice Planning Agency. Additionally, he functioned as an International Judge for the United Nations Mission in Kosovo in 2005 and was honored with the Iowa Judges Association Award of Merit in 2008.