> I don't want to vote in a way in which my statement is that I equally prefer the Democratic candidate to Green Party candidate.

This is a pervasive logical fallacy, we call the "expressiveness fallacy". https://sites.google.com/a/electology.org/www/expressiveness

In short, you could allow partial approvals (1/4, 1/3, etc.), or mathematically equivalent ratings on a 0-N scale. But Approval Voting behaves almost as well in aggregate. http://scorevoting.net/BayRegsFig.html

And IRV/RCV will maintain two-party duopoly. https://asitoughttobe.com/2010/07/18/score-voting/

Voting theory is highly counterintuitive.