In November 1962 Railsback was elected as a Republican to the Illinois House of Representatives. Four years later, in the 1966 election, he was elected to the U.S. House of Representatives, defeating the DemocraticincumbentGale Schisler. Although inspired to enter politics by the staunchly conservativeBarry Goldwater, Railsback was a moderate Republican while in the House. A longtime member of the House Committee on the Judiciary, he participated in the 1973–74 impeachment process against PresidentRichard Nixon. Railsback and his Democratic colleague Walter Flowers led what Railsback called a "fragile bipartisan coalition" which crafted two articles of impeachment against Nixon, charging him with: obstruction of justice in attempting to impede the investigation of the Watergate break-in and abuse of power by misusing the authority of the office of the presidency on multiple occasions, dating back to the first year of his administration. He, along with five other Republicans, voted with all 21 Democrats in advancing these articles to the House floor. In an emotional July 24, 1974 speech on the House floor, he said that his obligations to uphold the Constitution superseded his personal loyalties to Nixon, a friend who Railsback praised as having many significant achievements. Support for Nixon's impeachment among congressional Republicans was the key factor leading to Nixon's decision to resign his office the next month. Despite the vitriol voiced against him by pro-Nixon commentators and constituents, he went on to be re-elected four more times. While in the House, Railsback had a key role in the passage of the Juvenile Justice and Delinquency Prevention Act of 1974. In 1979, he and Wisconsin Democrat David Obey co-sponsored legislation to reduce the influence of political action committees in election spending. He opposed Ronald Reagan's effort to abolish and eliminate funding for the Legal Services Corporation, which provided legal aid to poor Americans. In 1980, Railsback was one of three U.S. House members, along with future Vice PresidentDan Quayle of Indiana and Tom Evans of Delaware, involved in the controversial Florida golfing trip with lobbyist Paula Parkinson. Over eight terms in office, Railsback had established strong political support in his district; the Washington Post noted that "He took what might have been a marginal district—a mixture of rural Republican counties and a labor stronghold in Moline-Rock Island—and built a secure political base by salting his GOP voting record with support for civil rights and some labor positions." In 1982, however, Illinois had lost two districts in reapportionment after the 1980 census, and through redistricting, Railsback's district changed in composition to become significantly more conservative. He was defeated for renomination in the 1982 Republican primary by a considerably more conservative Republican, State SenatorKenneth G. McMillan. McMillan was defeated by Democrat Lane Evans in November. Railsback was a mentor to Raymond H. LaHood, who worked for Railsback from 1977 to 1982 before becoming a U.S. Representative himself, and later U.S. Secretary of Transportation in the Obama administration.
Railsback married Patricia Sloan in 1955, and they had four daughters. The marriage ended in divorce. Railsback later married Joyelyn Railsback, known as Joye. He had 19 grandchildren. Railsback retired to Idaho, where he and his wife lived in McCall and Meridian. He died on January 20, 2020, in Mesa, Arizona, after a period of declining health.
