We’re doing this in other threads right now.
3rd parties simply don’t work under the US system. They can’t work by the physics of our electoral laws.
Which is exactly why historically both the Rs and the Ds have been fairly “big tent” parties.
In a parliamentary system, and especially one with proportional representation for some or all of the legislators, the USA would probably have 10 parties: 2 or 3 biggies and an ever-evolving set of 6+ almost-single-issue / protest parties. Under that scenario our politics would look a lot like Italy’s or Israel’s.
In our system somehow all those protest parties and even a 3rd “middle-way” party, have to fit under the R or D brand. The parties can change names over time, they can change platforms, but they can’t change their number. “To two shalt thou count; never unto three.” And we hope very much to never be counting to just one, no matter how much the seditionists want that right now.
So the Rs need somehow to contain the nationalists, the white supremacists, the evangelicals, the rich anti-tax / anti-regulationists, the military industrial complex hangers-on / apologists, and the know-nothings.