Can't do it. Because not only are their votes being thrown away, every failed attempt to win is making life worse for millions of fellow citizens.

How's that for a selling point? "We're great--we just made your life worse because the greater of two evils won because of us. So, vote for us next time!"

It's a complete non-starter.

The only options are: win in one go, or don't play.

If you want to start gradually, forget political parties entirely. Work on voting methods. Switch to IRV or some other ranked-choice method where running as a third party doesn't have a spoiler effect.

Once you have a voting method in place that doesn't make you punish exactly those people who are most interested in supporting you, then you start at whatever level you've made the change.

Because it's easier to get local or state changes to voting methods than national ones, you'll probably be starting local at that point. But it's really a requirement--about as much as needing to open a garage door before driving a car out of the garage.