He bought into the RNC's post 2012 'autopsy report', particularly with regards to immigration. He thought that by being the candidate that the RNC believed could win the general election, he could amass establishment support and cruise to victory.
His strategy had a few big flaws:
1.) Establishment support isn't what it used to be. He may have been the establishment frontrunner for a while, but being the face of the establishment wasn't a good play in the current environment.
2.) His campaign has also floundered from a more technical standpoint. He's been awkward and gaffed a lot on the campaign trail, his debate performances have been lackluster, he's let himself be used as a punching bag by Trump. Despite the current mood of the electorate, if Bush had run a good campaign, he would be in a much more viable position.
3.) I suspect that Bush may have made the same mistake as Walker and spent too much too early. He probably believed that the money would keep pouring in. Now that the flow has ebbed, Bush is in a very unsustainable situation. Its even possible that his campaign has a time limit due to money problems.
This is a pretty good analysis. His money is running out, his execution has been poor, the establishment cred hasn't helped as much as he'd like, and now he has to deal with Rubio. I'd guess he's now on a hard time limit of "before Xmas", but I think there's still a path to victory.
With Carson in the early stages of collapse Bush is going to need to be
the leading old-guard candidate before the holidays, being in at least the #2 spot overall or close to it, or I expect he'll pack it in. And to do that, I think he needs to take down Rubio.
I don't know if Jeb is actually capable of it, but it shouldn't be that hard. Mention Rubio's inexperience and personal finance questions, then point out the leadership experience of the governors and corporate executives on the stage. Say that Rubio is a good guy, but isn't ready to be President, and then wrap up by saying "America can't afford to have another first-term Senator learning on the job". (Or something like that.)
Blow Rubio out of the race, then get Kasich (maybe Christie?) to endorse him. Follow it up with the narrative that "Thank God Jeb is here to save us from the likes of Trump and Carson" (without alienating their supporters too much) and then it turns into a three-way race between Trump, Bush, and whoever picks up the social conservative mantle (probably Cruz). It's still far from in the bag at that point, but eminently winnable. But Bush
needs Rubio out, and he'd be best off doing it himself at the next debate. But I have no idea if he can pull it off.
