Donald Wayne Riegle Jr. (/ˈriːɡəl/ REE-gəl; born February 4, 1938) is an American politician, author, and businessman from Michigan.

[2] Riegle defeated incumbent Democratic U.S. Representative John C. Mackie, to be elected from Michigan's 7th congressional district to the 90th Congress.

[2] In 1973, Riegle changed party affiliation to become a Democrat over differences with the Nixon-Agnew Administration regarding the Vietnam War and the "Southern strategy".

Sponsored by Congresswoman Bella Abzug, the Equal Credit Opportunity was passed by the House and the Senate in 1974 and was signed into law by President Gerald Ford on October 28, 1974.

Riegle's 1988 election was the largest Democratic margin of victory in the state's history until being surpassed by Carl Levin in 2008.

The legislation also provided increased consumer protections for high rate home equity loans, contained measures to increase credit availability to small businesses, streamline the regulation of depository institutions, and reform the National Flood Insurance Program.

In 1994, Riegle led an investigation of the illnesses being experienced by veterans of the Gulf War, using the jurisdiction of the Senate Banking Committee over "dual use" exports—materials and technology that could be converted to military use.

The resulting investigative report to the Senate detailed at least three occasions on which U. S. military forces came into contact with chemical warfare agents that may have led to the development of Gulf War syndrome and that at least some of those biological agents (weapons of mass destruction) had been provided to Saddam Hussein by the US.

The book provides an inside look at the workings of Congress, Riegle's opposition to the Vietnam War, and his break with the Nixon White House.