Final answer:
The key political parties in the US are the Democrats and Republicans. Third parties such as the Libertarian and Green Party have had significant influence in certain elections, including the Green Party in 2000. The winner-take-all system makes it difficult for new parties to gain traction, despite their potential to influence major party platforms.
Step-by-step explanation:
The most powerful political parties in the US are the Democrats and the Republicans. Influential third parties include the Libertarian Party and the Green Party. Most analysts agree that the Green Party had a significant effect on the 2000 presidential election.
It is challenging for a serious third party to emerge in the United States, positioned ideologically between Democrats and Republicans, due to the entrenched two-party system. The winner-take-all electoral system, historical precedents, and party loyalty are factors that hinder the success of third parties. However, third parties can impact elections by introducing new ideas and influencing the platforms of the major parties.
Political parties are considered linkage institutions; they connect the electorate with their officials and sometimes serve elite interests. In the U.S., parties facilitate government business, but whether a unified party control or a divided government is preferable is a subject of debate. Generally, third parties face systemic challenges but have occasionally played notable roles in shaping U.S. politics.
According to the learning materials, there are three basic types of third parties in the U.S.: those that form around strong personalities, those advocating specific issues, and those representing ideologies not found in the major parties.
The national level of party organization is most responsible for helping the party's nominee win the presidency.