You are not the first to say that Sinij, however there are a couple things to consider.

1) Though a powerful minority, the religious extremists are still a minority in the GOP.

2) The system has been gamed, gerrymandered and rigged to such a degree that 3rd parties face institutional resistance from govt itself. Not to mention the momentum of the existing party apparatus.

I think its more achievable to enact change by co-opting the system, as opposed to trying to build something new from the ground up.

Unfortunately our system is now a two party system for all practical purposes.

For who could be free when every other man's humour might domineer over him? - John Locke (2nd Treatise, sect 57)