What are benefits of the two-party system for the US?

When one party is elected in a two-party system, they represent a much larger portion of the population than a party would in a multi party system where they would represent only a small fraction of the total population of the country.

Also, even if voters haven't followed an election, they know which party they identify with usually, and they can vote based on that.


(an added bonus is debates between candidates are way better between only two people. Imagine a nine person debate.)