The Republican civil war
Unfortunately the Republican establishment doesn't quite have standing to assert a narrative of itself and the teabaggers as distinct rival factions fighting for control of the party, even if that's emerging as the de facto situation. Who led the bull into the china shop in the first place? Who put doofuses like Ted Cruz and Rand Paul and Ted Yoho into positions of power? Who enabled and facilitated their destructive behavior? Without the imprimatur and support of the Republican party, they could not have been elected. Without the collaboration of mainstream figures like John Boehner (who is still blocking a House vote on clean CR and debt-limit bills which could pass with a few sane Republicans voting with the Democrats), they could not have held the country hostage.
After Obama took office, when the Tea Party first arose in all its paranoid race-baiting spelling-challenged glory, the Republican establishment was happy to exploit its rabid energy and ride the tiger to victory in the low-turnout 2010 election. Even when primary-spawned nutbars cost the party Senate seats in Delaware and Nevada, criticism was muted. The tiger was dangerous, but it was useful to the agenda the establishment has successfully pursued for decades -- tax cuts, deregulation, and attacks on the welfare state, which have exploded the deficit, held the bottom 99% in economic stagnation, and concentrated wealth more and more in the hands of a tiny, obscenely-wealthy minority (not such a "moderate" agenda, in fact).
Nor is this the first time the Republican establishment has joined forces with a movement of dangerous fanatics in order to profit from their zeal. In the late 1970s the party embraced the rising new Christian Right, unfazed by its anti-gay, anti-female equality, anti-science, anti-modernity fervor, or by the theocratic totalitarian implications of its ambitions. The fundies helped get Reagan elected, and the alliance has been tightening ever since. It was only after forced ultrasounds and gay-baiting and slut-shaming and "legitimate rape" started losing elections that the establishment started gingerly trying to dissociate itself from the crazies.
And now that the latest bunch of nuts has come within an inch of wrecking the global economy that the financial parasite class depends on almost as much as the rest of us do, the establishment wants to disown them and go back to being a sane party and accepted as such.
Sorry, but after a premeditated criminal fuck-up of this magnitude, you don't get to bounce back. You can't just say "sorry," hit the reset button, and wipe the slate clean. You enabled this. You put the Christian Right and then the Tea Party into positions of power, knowing full well what they were and what they wanted to do. You don't deserve the chance to redeem the Republican party. It needs to be smashed and destroyed and flushed out of our country's political system forever. The nuts are fighting back and I hope they and you obliterate each other. You knowingly and willfully tried to sacrifice the prosperity and freedom and human rights of millions of Americans for the sake of your own political power and greed. If this is the end, it's the end you wrote for yourselves.
To hell with you.