The reason republicans end of accepting new government programs like obamacare is simply because voters want free stuff and politicians want to get elected.
I used to think the answer to reducing government was to change the voting laws to some sort of net taxpayer rule but now I think it's either too easy for the government to get around the rules or the rules are too invasive. My top contender now is to end the fed. With real free market money, it's more likely that voters will feel the downside of that "free stuff" because the government will have to raise taxes.