You may want to go back somewhat further and analyze how the GOP came to be. Perhaps, in the short term, voting 3rd party will help elect Democrats, but that could well change rather shortly should the GOP get a clue.
However, the best remedy, IMO, is to withhold all funding from the GOP (at least that which we have control of...). Get active in local GOP politics, go to meetings, let our voices be heard. Let the party know that we are not on board. Not until they begin promoting viable conservative issues and candidates.
Take Illinois for instance. Andrew McKenna is the former GOP state chairman. He's now running for governor on the GOP ticket. He's RINO all the way and I'll not vote for the man. I've already passed that on to my state reps (who I'm acquainted with). I'm also actively getting that message out to all I know.
The GOP here is 'business-as-usual', and that's not good enough. Consequently, I'm not on board.
I've thought about this a bit. Do you know what percentage of funding comes from rank and filers, and what percentage from corporate/SIGs? Asking because it makes a difference. If they don't need your money, they won't care.
though i am a bit rusty with political history this nation was still relatively young - political parties had not really congealed into anything remotely like we have today until Andrew Jackson’s Dems. We can quibble all we want and though i understand the frustration you feel particularly in a blue state such as IL do you honestly think a true blue conservative can win there? like MA only Rs who can get elected are either Moderate or all out liberal (at least socially) which is one reason i left there. the candidates who are most likely to be successful going forward are people like McDonell in VA who is as far as i can tell Conservative but campaigned on bread and butter economic/middle class issues and downplayed his social conservatism. Same went for Christie in NJ. Fiscally conservative folks who downplay social issues will win. its a sorry state of affairs but people who are stereotyped as “conservative neanderthals” will most likely lose in most statewide or “moderate” areas of this nation. Third parties who shriek and moan will not win, split the right or right leaning or anti-incumbency vote and allow the full fledged commies to continue their reign.