Curtis was elected to the House of Representatives in 1938 on an anti-Franklin D. Roosevelt and New Deal platform. He served in the House from 1939 until 1954, being reelected every two years. Curtis ran for the United States Senate from Nebraska in 1954 and won the election, then after incumbent Sen. Hazel Abel resigned, he was appointed on January 1, 1955, getting a two-day jump on seniority. Incidentally, the fifteenth Senate term for Nebraska's Class 2 seat, which lasted from January 3, 1949 to January 3, 1955, was unusual in that it saw six Senators serve. Curtis was the sixth and last of these. He was reelected threemoretimes to six-year terms, serving from 1955 to 1979. Curtis voted in favor of the Civil Rights Acts of 1957, 1960, 1964, and 1968, as well as the 24th Amendment to the U.S. Constitution, the Voting Rights Act of 1965, and the confirmation of Thurgood Marshall to the U.S. Supreme Court. Curtis was loyal to the Republican Party, particularly supporting its anti-communist stances and fiscal conservatism, which included opposition to social programs such as the New Deal and President Lyndon B. Johnson's Great Society. During the 1963 investigation of bribery allegations against Democratic Party organizer Robert Baker, Curtis supposedly leaked a secret memorandum to advance his own positions. A close ally of both Barry Goldwater and Richard Nixon, Curtis served as floor leader during the 1964 Republican National Convention, when Goldwater won the nomination. During the early 1970s, Curtis supported President Richard Nixon's Vietnam War escalation policy, and remained loyal to him throughout the Watergate Scandal. On August 6, 1974, two days before Nixon resigned, he implored Congress not to panic. He warned that the United States would become like a "banana republic" if Nixon was ousted in favor of Vice President Ford, who in turn would then select someone to fill the vice presidential slot. He said "this would mean both Ford and the new Vice President would be men who hadn't been elected to their high office, but merely nominated by a President under procedures for filling the vice presidency when it is vacant." Curtis served as chairman of the Senate Republican Conference from 1975 to 1979.
Later life
Following his retirement, Curtis moved to Lincoln, Nebraska, where he practiced law, served as an officer of the conservative lobby the American Freedom Coalition, and gave occasional interviews to the media. Curtis died in Lincoln on January 24, 2000, and is interred at Minden Cemetery in Minden, his longtime hometown. Following his death, he was praised on the Senate floor in a speech delivered by Strom Thurmond, a contemporary of Curtis's who was also elected to the Senate in 1954.
