Final answer:
The U.S. uses a 'Winner-Take-All' electoral system, also known as 'first past the post', where the candidate with the most votes wins. This system is used in Presidential elections where states' electoral votes are awarded in a winner-take-all manner, barring Maine and Nebraska.
Step-by-step explanation:
The electoral system in the United States can best be described as a Winner-Take-All system, particularly the variation known as 'first past the post' in its federal and most state elections. In this system, the candidate with the highest number of votes wins, regardless of whether they secure a majority. This system is evident in the allocation of electoral votes in the Presidential election, where except for Maine and Nebraska, all of a state's electoral votes go to the candidate who wins the majority of the popular vote in that state.
As a result, smaller parties find it difficult to gain political power, and candidates can win with less than a majority if there are multiple candidates. This contrasts with Proportional Representation, which allocates seats based on the percentage of votes each party receives, encouraging a multi-party system - a system not employed in the U.S.