Two-party system
A two-party system is a party system where two major political parties dominate the government. One of the two parties typically holds a majority in the legislature and is usually referred to as the "majority" or "governing party" while the other is the "minority" or "opposition party". Around the world, the term has different senses. For example, in the United States, Jamaica, and Malta, the sense of "two-party system" describes an arrangement in which all or nearly all elected officials belong to one of the only two major parties, and third parties rarely win any seats in the legislature. In such arrangements, two-party systems are thought to result from various factors like winner-takes-all election rules. In such systems, while chances for third-party candidates winning election to major national office are remote, it is possible for groups within the larger parties, or in opposition to one or both of them, to exert influence on the two major parties. In contrast, in the United Kingdom and Australia and in other parliamentary systems and elsewhere, the term "two-party system" is sometimes used to indicate an arrangement in which two major parties dominate elections but in which there are viable third parties which do win seats in the legislature, and in which the two major parties exert proportionately greater influence than their percentage of votes would suggest.
Liberalism in the United States
In the 1950s and 1960s, both major U.S. political parties included liberal and conservative factions. The Democratic Party had two wings: on the one hand, Northern and Western liberals, on the other generally conservative Southern whites. Difficult to classify were the northern urban Democratic "political machines". The urban machines had supported New Deal economic policies, but would slowly come apart over racial issues. Some historians have divided the Republican Party into liberal Wall Street and conservative Main Street factions; others have noted that the GOP's conservatives came from landlocked states (Robert Taft of Ohio and Barry Goldwater of Arizona) and the liberals tended to come from California (Earl Warren and Paul N. "Pete" McCloskey), New York (Nelson Rockefeller), and other coastal states.