Final answer:
Major parties view minor parties as spoilers because they can take away votes and potentially cause them to lose elections. The two-party system dominates in the US due to the 'winner-take-all' rule and strategic voting. The major parties also have advantages over minor parties that make it difficult for them to gain support.
Step-by-step explanation:
The major parties view minor parties as spoilers because they can take votes away from one of the major parties and potentially cause them to lose an election. In the United States, the two-party system dominates because most states have a 'winner-take-all' rule, meaning that only one winner can emerge from an election. As a result, voters often cast strategic votes for the major party candidates they believe have a better chance of winning, making votes for minor party candidates less effective. Additionally, the major parties have advantages such as easier access to the ballot and official roles in government that can make it difficult for minor parties to gain popular support.