Bullet-point style, looking ahead...
* The government shuts down if Congress doesn't act today. There is still, however, plenty of time if everyone cooperates to do a short-term extension, whether it's a one-day, one-week, or any other length.
* The House can do that easily if Republicans want it. In the Senate, it could be blocked by one Senate...however, it would make little sense for any Senator to do so (which doesn't mean that Cruz or Lee won't, but I don't think they would).
* If Republicans (or, for that matter, Democrats, although the latter seems extremely unlikely to me) back down at the last minute...no harm done. Everyone bluffs; if this is all a bluff, then a lot of the claims about GOP norm-defying in this case are massively overblown.
* Along with that: a very short term shutdown, really anything up to a week, isn't all that big a deal. Most past shutdowns were like that; if we get one of those, it's really more hype than anything else. Yes, it costs some money, and inconveniences some people, but it'll be forgotten rapidly.
* However: the same dynamics that get us to shutdown are fairly likely to produce a longer one.
* Yes, House Republicans will begin to hear complaints about the shutdown from the start. But at least for a while, those complaints will surely be outnumbered by partisans urging them to fight on.
* That's particularly true if Republicans really are testing the theory that a shutdown will eventually produce a major public opinion swing in their favor, with people joining them in saying that Democrats should just give up ACA in order to get the government opening. I think that's a crazy theory, but if they believe it, then the next logical step would be to wait and see whether it works.
* Basically, if Boehner is deliberately moving to a shutdown in order to teach his conference a lesson (and there are hints of that in the reporting), he's making a bad move.
* On the other hand, if there's a plan to retreat within a day or two that doesn't rely on Republicans suddenly coming to their senses...that seems like a silly plan to me, but again, a very short shutdown is no big deal.
* I suppose I can imagine at least one way it might make some sense: if many Republicans really believe that Obama (and Senate Democrats) are bluffing and would never allow a shutdown over Obamacare.
* But otherwise, if Boehner thinks (or if mainstream conservatives think) he can get a controlled one or two day shutdown, he's playing with fire. There's going be a lot of pressure to "fight this through to the end," and only moderate, if building, pressure to end it quickly.
* All of which is why I've always thought that Boehner's best move was to avoid a shutdown, and why I still think there's a fair chance he'll avoid it.