Considering that Carson leaving would be for reasons that would likely also cause Trump to leave, and probably Cruz as well, people WOULD notice headlines like “Trump, Cruz and Carson leave rigged GOP primary process to start 3rd party”, taking a huge number (quite possibly winning) of votes with them.
Cruz is a serious contender. Trump is a serious contender. Carson isn’t.
If that happens, then it guarantees Hillary wins.
Not saying starting a new party and abandoning the GOP isn’t a good idea in some ways. Just saying, if it happens in 2016, and the GOP convention becomes a circus and collapses, with some going independent or 3rd party, Hillary wins the general election easily.
Any such plans have to look beyond 2016, is what I’m saying. Is there staying power on the part of various conservatives to build a new political party to compete in 2020 and beyond? That’s what I want to know.