If I behave like a Republican, then R's and D's keep winning. Nothing changes.
If I keep doing what I'm doing, R's and D's will keep winning. Nothing changes.
So why do I need to join the R's? At least I have my integrity and principles. I didn't even vote for Gary Johnson last election because he lost me. He wasn't representative enough. If everybody acted like me, democracy would work a lot better. I'm leading by example. It may not change anything, but neither does voting for the lesser of two evils.