I agree if Rubio can consolidate and get dropouts before NH he has a shot, but I dont think that is going to happen. I think the big money and most of Congress and the GOP Govs are waiting to see what happens in NH. The Govs may especially feel some loyalty to Christie as he was head of RGA and did a good job so they are likely not to turn on him until he is done.
Also the Union Leader already endorsed Christie. So again, the establishment is basically paralyzed until NH is over. But will it be too late?
I think it might be too late now, and that we're already looking at nominee Cruz (or a convention fight). All because "the establishment" doesn't
have a good candidate. The closest they have to an Establishment Not-Trump (or ENT) are Bush, Kasich, Christie, and Rubio. All of them are problematic. Rubio once looked good after Bush's downward spiral, but his complete and utter failure to seize anything, leverage his momentum, or even run a good campaign has tarnished him.
What the establishment needs to do is somehow pick the least bad of them, get the others to drop out
before NH, and then have the ENT win NH over Cruz and Trump. But there's no good mechanism to do that, except NH itself. And, with all (or most) of them
in NH, it's filtering effectiveness is greatly weakened.
It's not that hard to see a situation where two or more ENTs stay in through (or beyond!) Super Tuesday. Sure, they'll be behind Cruz and Trump in the delegate count, but with such a split its increasingly more likely that the convention will be brokered, which in turn makes staying in, even with a handful of delegates, make more sense.
Or maybe enough people will drop out after IA that NH will be won by an ENT, and the ENT and Cruz will duke it out above the increasingly bellicose and irrelevant Trump, with Cruz eventually playing a slightly stronger Santorum role. And then we'll all look back at how crazy we thought it could get and laugh at how credulous we were.