Final answer:
The concept of a 'major party' historically refers to the two dominant political parties in the United States, the Republican Party and the Democratic Party. These parties have a realistic chance of winning elections due to factors such as the structure of U.S. elections and voter support.
Step-by-step explanation:
The concept of a 'major party' historically refers to the two dominant political parties in the United States, which are the Republican Party and the Democratic Party. These parties have a realistic chance of winning elections due to various factors, including the structure of U.S. elections and the support they receive from voters. While other minor parties may exist, they often lack the widespread support necessary to win significant political offices.