Politics in America are often compared to a pendulum, forever swinging back-and-forth between right and left, shifts to one side invariably countered over time by shifts back to the other side. Such is the case in discussions of conservative and liberal movements in the United States. Disillusionment with the dominance of one party will predictably result in the majority of voters deciding a change is in order and electing into power the opposing political party. In the 1964 presidential election, conservative Republican Barry Goldwater had hoped that public disillusionment with liberal policies would swing the electorate in his favor. Goldwater and his followers were wrong, as incumbent Lyndon Johnson handily defeated the Republican ticket in that election. Later, during the 1980 election, public disenchantment with the presidency of Jimmy Carter, a liberal from Georgia who had ridden a wave of anger towards Republicans resulting from the Watergate scandal, was manifested in Carter's failure to win his campaign for reelection. Carter's weakness as a chief executive and perceptions of a growing military threat from the Soviet Union helped propel the conservatives to a major victory, led by newly-elected President Ronald Reagan. Reagan's pledge to rebuild the American military, to more robustly confront the Soviet Union, and to repair an economy still reeling from the inflationary pressures and energy crises of the 1970s, constituted one of the most important advances in conservative policies in the post-World War II era.
The conservative platform of a strong national defense, fiscal discipline, lower taxes, opposition to abortion, and other tenets central to the philosophies of the Republican Party was very successful politically during the 1980s, despite noted inconsistencies in fiscal practices. While Reagan's eight-year presidency was followed by the election of his vice president, George H.W. Bush, the latter's administration, as with Carter's a decade before, failed to win its bid for a second term, as the political pendulum predictably swung to the left and the election of William Clinton, whose eight years in power were followed by George W. Bush's eight years as president, which is being followed by Barack Obama's two terms as president. In other words, conservative principles hold sway until the public tires of them and elects liberals in their stead. Liberalism has remained influential for the same reason conservatism has remained influential: the American public is fairly moderate on the whole and tires of single-party domination of the federal government. The American electorate remains seriously divided on a host of issues, including gun control, abortion, tax rates, and so on. By the time any one presidency reaches the end of its second terms, however, the public is generally ready for a change. Lyndon Johnson may have successfully defended his presidency against Barry Goldwater, but Hubert Humphrey couldn't beat back the challenge from Richard Nixon because of the public's anger over the Democratic Party's inability to extricate the nation from the war in Vietnam and because of anxiety regarding the levels of social turbulence the nation had been experiencing. That the Nixon presidency would fall victim to that individual's inability to achieve "peace with honor" and his paranoia regarding the political machinations of his opponents -- a psychosis that would lead to the aforementioned scandal that led to the Carter Administration -- was further testament to the fact that, irrespective of ideological underpinnings, the public will with absolute certainty tire of whichever party controls the government. That is why conservative and liberals both remain influential politically and culturally. At the end of the day, the American public is divided roughly down the middle on a large spectrum of issues, and the pendulum will continue to swing from one side to the other.