system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does America only have 2 powerful political parties?
gpt
It is the result of our flawed voting system.

Our voting system is known as first past the post, meaning the first person to reach a certain amount of votes wins. This has a flaw, known as the spoiler effect, where if multiple parties exist, people will vote for a candidate that has a better chance of winning instead of one that better aligns with their ideas to prevent another candidate from winning. Say for example, you better align politically with Gary Johnson this election, but would rather prevent Trump from winning, so you vote for Clinton to have her win instead of Trump.