Development of the Two-Party System
Political parties as we know them today developed in the mid-19th century. The Democratic Party grew out of Andrew Jackson's belief that common people, as opposed to the wealthy, should have more say in government. In the modern era, the Democratic Party is one of the two major political parties in the United States, typically more liberal in political ideology. Democrats tend to accept a greater role for government in people's lives. The Republican Party was formally founded in 1854 when several groups combined to oppose slavery. Six years later, the Republicans won the presidency when Abraham Lincoln was elected. The modern Republican Party is one of the two major political parties in the United States, typically more conservative in political ideology. Republicans tend to prefer low taxes and less government.
At the most basic level, parties seek to attract people to support their candidates. When citizens register to vote, they are generally given the option of registering as the member of a party or as an independent. Those who join a party as official members are called the rank and file. As party members, they can participate in party functions, such as meetings where candidates are nominated for office, though only the most committed members do so. They can vote in all primary elections, even those that are closed to nonparty members. A primary election is an election in which voters select the candidates who will run in the general election.
Political scientists seeking to understand partisan behavior divide citizens into three groups. Strong party identifiers consider themselves closely aligned with the party's goals and principles. People in the "strong" categories for a party are also described as that party's base—the group of voters who almost always support a particular party's candidates. These party identifiers are most likely to vote in party primaries. Many political analysts believe that the outsize role that members of the base play in primaries has contributed to increased polarization of American politics in which extreme differences in positions between the two major political parties have appeared and are strongly held. For example, the base—which strictly adheres to the party's ideology—may insist on the ideological purity of their candidates. When the bases of both parties behave in this way, the candidates they nominate are more likely to be further apart on where they stand on important issues and less able to compromise on government action.
Weak party members tend to identify and agree with a party's ideas and candidates but show more flexibility. They may split their ticket when voting, voting for members of their party for some offices and for members of another party for other offices. Because they are less committed to the party than the base members, they may also choose not to vote in primary elections but only in general elections. A person in the "independent" category for each party is called a leaner, a nonaligned voter who tends to favor the programs and candidates of a particular political party but does not firmly identify with that party.
Some individuals are purely independent, a voter who chooses not to align with any political party. Studies show that these voters are independent for three major reasons. First, they believe that the two major parties care more about special interests than about average Americans. Second, they agree with Republicans on some issues but with Democrats on others. Third, they do not trust either party.
Party Identification from 1972 to 2012