How long can Jeb survive with under-10% polling and poor debate performances?

[Averroës Nix]

I predict that he'll be out of the race by the end of the year, barring an unlikely turnaround in either national or early state polls.

There's no reason for Jeb to remain a candidate if he gets stuck in low-single digits, whether he has nine-figures in SuperPAC money or not, and at some point between now and then he'll lose  all but a few vestiges of the institutional support that has propelled him this far.

In the absence of some kind of implausibly elaborate conspiracy, I don't know how he'll improve his standing over the fall, or even arrest his protracted decline. He really is a tremendously weak candidate, and comparisons to Romney and McCain are unfair to both former nominees.

There's always the "but someone has to win" argument, I guess, but I don't think there's anything special about Jeb. Anything he can do, there's someone in this field who can do it better. (Well, aside from raising SuperPAC money, at least.)