Senator Don Nickles is currently the assistant majority leader for the Republican party.  In 1998, he became the first Oklahoma Republican ever elected to a fourth term in the U.S. Senate.

Nickles was first elected to the Senate Republican Leadership in 1988 when he was selected by his colleagues to chair the Republican Senatorial Committee. He was next elected to three terms as Chairman of the Republican Policy Committee. In 1996, and again in 1998, he was selected unanimously to be assistant majority leader.

Nickles serves on the Senate Finance Committee, Energy and Natural Resources Committee, Budget Committee, and Rules and Administration Committee. He is chairman of the Social Security Subcommittee of the Senate Finance Committee and chairman of the Subcommittee on Energy Research, Development, Production and Regulation.

Throughout his Senate career, Nickles has worked toward a more responsible and less intrusive federal government. He has been a consistent proponent of a family-friendly tax system, and created the $500-per-child family tax. He led efforts to reform the Internal Revenue Service; helped enact the nation's first balanced budget in three decades; and passed laws to make members of Congress accountable to the same laws as everyone else.

Nickles' career in public service began with his election in 1978 to the Oklahoma State Senate where he served two years.  In 1980, at age 31, he became the youngest Republican ever elected to the U.S. Senate. 

Nickles is one of the few members of the United States Senate with a background in small business. He worked his way through Oklahoma State University by starting a janitorial service. Following graduation, he went to work for Nickles Machine Corporation in Ponca City, Oklahoma, where he later became vice president and general manager.

Nickles and his wife, Linda, were born and raised in Ponca City. They have four children.