Trump, Carson, and Cruz are basically the cancer eating away at the inside of the GOP, which effectively paralyzes its efficiency outside of local and state elections. The blowback of the 2008 elections is still alive and well, and its not stopping any time soon.
From what I can tell you've got a sort of divide among the party between moderates/slightly liberal Republicans and the sort of insanity of the conservatives and the far right basically hijacking that sector. Honestly, this split was in the making by the 80's but now it's really hammering home in the worst possible ways. Attaching yourself nearly fanatically to the Evangelicals doesn't leave you a lot of room to do the 'sausage making' of politics, because they're VERY much opposed to conceding a point here in order to win one there. As far as I can see, the Tea Party is going to keep trying to hijack the party as they have for the past 8 years, but this is going to end very very badly. Moving further to the right and pandering to the conservative base is not helping with popular elections. Neither is digging in on issues that you've already lost, and have lost for the last fucking decade and beyond. Fighting gay marriage now is a lost cause, religious liberty is a can of worms that could backfire like a hot potato because of the (surprisingly pervasive) opinion among Evangelicals that non-Christians aren't protected under the 1st amendment, and abortion has been a stalemate for years upon years.
Mind you I'm saying this as a total outsider and my opinions are probably entirely off but this is how I see it. Sort your own house out Republicans, before you try to sort the nations. For fucks sake, if Carson and Cruz are serious contenders you have an actual problem.