You have to understand the psyche of people in power. Their prime motivation is to keep themselves in power. They pay lip service to voters, but do their utmost to entrench themselves. It is true for both parties. All are happy with gerrymandered districts. All are happy with playing the game of favoring companies or unions with beneficial legislation in exchange for campaign contributions that makes their seats safe. And it’s not just elected officials. It is the press who enjoy the prestige of getting the interviews outsiders can’t get. Playing footsy with the power structure has its rewards, even if they have to ignore stories like John Edwards, and his mistress and love child during the 2008 nomination process. It took the National Enquirer to break that story, not the NY Times or the LA Times.
Donald Trump has caught the imagination of not only conservative Republicans, but the country as a whole. When was the last time 25% of African Americans favored a Republican candidate? The RNC has never had an action plan to do that. Yet it is happening. The RNC is staring victory in the face but aiming for defeat. Its godchild Jeb Bush is facing a 7% polling number, a quarter of Trump's. He has tons of campaign money but it’s not working. He has loser painted all over his face. He is another McCain and Romney, and he will suffer the same fate.
Even worse, if the RNC purges Trump from the party and loses the election, there will be a new third party. They haven’t factored that in, but it will happen.