It seems that the opinion of "The Narrative" is basically that John Boehner and Republican House Leadership (and various moderate Republicans) are forced to do the Tea Party's bidding. Because to do otherwise would be to jeopardize their leadership positions. We know Conservatives love this narrative, it makes them feel powerful while simultaneously avoid reality by always claiming every defeat is due to weak leadership.
So I want to offer a contrary theory: Boehner, et al., are essentially as extreme as the rest of the Tea Party - they are no moderates. They are just pretending to be in the hold of the Conservatives to enhance their own bargaining position. Someone as experienced as Boehner can't credibly claim to be stupid enough to shutdown the government or risk default. But he can claim to be stuck by his own extremist Tea Party faction - who are actually that crazy and stupid.
Below the squiggle, I'll point out a couple issues:
You can't force a Speaker out mid-term
"Coups" don't work. Never have. Boehner was actually part of one against Newt Gingrich - and it failed. You basically have to force the Speaker to accept a vote of no confidence, while simultaneously risking that the minority party could win a plurality. So, Boehner's finishing this term one way or another.
House Conservatives don't have an alternative candidate
OK, you might be saying, but can't they replace them at the beginning of next term? Yes, but they kind of already tried this. Several Conservatives voted for other Republicans - although no where near enough to actual threaten Boehner. What's more significant is that they all voted for different people. There is no obvious candidate that Conservative can agree on. Cantor is as hated as Boehner. Ryan, if you read Conservative website comments, is becoming persona-non-grata. And even if they did settle on an alternative, it would only raise the specter of a split ticket and Speaker Pelosi. Oh, also they have to actually win the midterm election, which is becoming slightly less of a sure thing. Basically, it's easy to threaten Boehner's Speakership - but actually pulling it off is way more difficult.
Boehner has defied Conservatives before
On the Fiscal Cliff, on Hurricane Sandy relief, and on the Violence Against Women Act, Boehner violated the "Hastert Rule." Conservatives where really, really, super angry ... until Fox News moved on to the next source of Conservative outrage. In all three instances, public opinion was so obviously against the Conservative opinion, Boehner didn't care. Well, isn't public opinion pretty obviously against Conservatives on the shutdown/default?
These House Conservatives are probably to lazy to do anything
Now, perhaps the this situation is different, or maybe it would be the straw that broke the camel's back. But consider this: are the Conservative back-benchers really any different than Sarah Palin? Palin, if you remember, is all bark and no bite. She wants to be on TV, she wants people to listen to her, but she really, really doesn't actually want to work hard (reading newspapers requires too much effort for her). Removing Boehner would take some real effort - effort that Conservatives have never really shown before.