But the majority of people do actually end up pretty closely aligned with one of the major parties. And btw, I'm not arguing that we wouldn't benefit from more parties.
Also, you're changing the subject. Remember that your other post claimed thinking people are independent and that's wrong. There are many intelligent, thinking Democrats and Republicans. And I'm not claiming that there are no thinking Independents, but in my experience most of them do actually closely align with a party and the ones that truly don't are usually totally fucking clueless about politics.
Someone who feels very strongly about liberal values will vote D and one who feels very strongly about conservative values will vote R (exceptions exist of course, but generally speaking). And this is true regardless of intelligence or how well informed they are.