I think there would be room in the USA for far more than two parties: religious/social conservatives who don't have a problem with big government, socially more liberal conservatives who want a small government and low taxes, moderate liberals/ordocapitalists, a labor party that focuses on economic fairness but doesn't care as much about identity politics and a socially progressive left that favors government intervention, etc.
I am leaving out Greens because ecology has become such a big issue and will become even bigger so that it becomes less and less a question of left or right and more one of HOW to solve these serious issues (for example here in Germany only the extreme far right denies human made climate change, all the other parties from normal conservatives to the left all just differ on how to reduce carbon footprints and what or how much to sacrifice in order to achieve that)
Unfortunately conservative "foundations" like State Policy Network (SPN) have spread a six point climate denial talking point:
1) CO2 is not actually increasing.
2) Even if it is, the increase has no impact on the climate since there is no convincing evidence of warming.
3)Even if there is warming, it is due to natural causes.
4) Even if the warming cannot be explained by natural causes, the human impact is small, and the impact of continued greenhouse gas emissions will be minor.
5) Even if the current and future projected human effects on Earth's climate are not negligible, the changes are generally going to be good for us.
6)Whether or not the changes are going to be good for us, humans are very adept at adapting to changes; besides, it's too late to do anything about it, and/or a technological fix is bound to come along when we really need it.
It's ALWAYS been about doing nothing. This is now GOP and conservative policy. People will need to decide if they want to stay with this lie or move on. I think some kind of reformed party is a possibility, maybe that can contain green policy too.
I like the idea of instant run-off voting and preference ballots, too.