Ross Douthat accurately frames the exciting new challenger:
[Newt Gingrich] suddenly has a clear path to the great prize of this Republican presidential campaign: The chance to finish a respectable second to Mitt Romney.
That Romney has all along been the inevitable nominee is beginning to soak into some pretty thick skulls on the far right (among whom Douthat is certainly not included). What alarms is that the profoundly squirrelly "resistance" has held so firm for so long, has maintained the majority, and has demonstrated an almost kamikaze eagerness to polish off what's left of the traditional GOP.
From here on out, the only real suspense will come in which faction -- the conservative or pseudoconservative -- opens a clear path to winning the party after it is, or so I suspect, crushed in 2012.