United States Senator Patrick McCarran represented the least populated state in the Union from 1933 to 1954. Despite Nevada's small size, McCarran was determined to make a significant mark for himself by expressing an opinion on major national and international issues. During his senatorial career, he had a considerable impact on the formation of many diverse issues affecting American policy.

When he became a senator in 1933, McCarran was fifty-six years old, hardly youthful for a newly elected member of Congress. He fought hard to obtain prized committee assignments, and to gain a reputation for independence. As a freshman in the Senate, he received appointments to important committees such as the Appropriations Committee and the powerful Judiciary Committee, which has control over all immigration bills, internal security matters, and appointments to the federal judiciary. He was also on the District of Columbia Committee, where he served as chairman from 1941 to 1944. It was through the Judiciary Committee, however, that McCarran was going to establish himself as a notable senator. By 1944, he had used his seniority to become chairman of this very important committee.

McCarran knew how to exploit power, and by the late 1940s had become one of the most influential United States Senators. He was by no means a member of the Senate's "inner club"—he was too much of a lone wolf and too ornery for that, and he did not get along with either President Franklin Roosevelt or Harry Truman. By mastering the legislative process, and by often using his clout ruthlessly, he parlayed himself into a position of immense power. For example, in July, 1952, the Washington Post disapprovingly stated: "It sums up the character of this congress to state an unquestionable fact: that its most powerful member was Patrick A. McCarran."

The senator from Nevada had deeply-held convictions regarding the usurpation of power by the executive branch of the government. He gained a national reputation with his important role in the battle to prevent President Roosevelt from stacking the United States Supreme Court in 1937. McCarran will also be remembered as the author of much landmark legislation such as the act which created the Civil Aeronautics Authority in 1938. Perhaps more than any other individual, he helped shape the passenger aviation industry in the United States in the 1930s. It is quite fitting that one of the leading airports in the U.S., that of Las Vegas, bears his name. His interest in aviation was a continuing one, and after World War II he became a champion of the idea that Pan American Airlines, headed by Juan Trippe, should be the sole American carrier operating from the United States to foreign nations.

McCarran was also a primary author of the McCarran Internal Security Act of 1950, an anti-communist law which required the registration of Communist Party members and their detention in concentration camps in time of emergency. He also supported the McCarran-Walter Immigration Act of 1952 which biased the quota system in favor of immigration from Northern and Western Europe. President Truman vetoed the two pieces of legislation, but Congress overrode his veto and passed both laws. In connection with immigration, McCarran did his best to prevent the influx of postwar refugees (especially displaced Jews) into the United States after World War II.

McCarran's name is also associated with some of the important investigations of domestic communism during the so-called McCarthy era. He was a friend of Joseph McCarthy's, but he was far more effective than the Wisconsin senator since he understood how to use the levers of power. McCarran chaired the Senate Internal Security subcommittee which examined United States policy toward China, subsequently destroying the State Department careers of John Carter Vincent, John Paton Davies, Jr., and John Stewart Service. He also forced the Justice Department to prosecute Asia scholar Owen Lattimore. He sincerely believed that internal treason in the State Department had resulted in the "fall" of China to the Communists, and he adamantly opposed any recognition of the People's Republic of China.

McCarran believed also that there was a single individual, unknown, masterminding the operations of the Communist Party in America, but he never found out exactly who that person was. He became gloomier in his later years, advocating the total eradication of Russian communism and, to obtain that, foresaw eventual war.

Patrick McCarran was a senator of great force and natural ability, and a master of the legislative process. The limitations of his education and world view, however, have subsequently diminished his reputation, and his most substantial legislative contribution remains in the field of aviation.